Magnetic Key Box, Hide A Key Holder, Under Car Magnetic Key Storage
4.6Editor score
Waterproof protection design
Compact portable size
Super strong magnetic hold
In this guide
Finding a reliable place to hide spare keys is essential for vehicle owners and travelers alike. A magnetic key box for under car provides discreet security against theft while ensuring quick access when needed. This guide reviews the best models available.
We evaluated ten highly rated products based on magnetic strength, weather resistance, size capacity, and durability features. Each option was assessed for real world reliability under various conditions including rain, dust, and rough terrain. Our analysis focuses on practical performance.
Every pick includes key specifications pros cons and detailed usage insights to help you decide quickly. Note that product details and availability may change over time. Always verify current information on the retailer page before finalizing your purchase decision today.
Top 3 Picks for Best Magnetic Key Box for under Car
Magnetic Key Box for Under Car with Combination Lock Box
4.2Editor score
Five strong magnets secure
Resettable combination lock
Durable ultra hard material
Hide a Key Outside with our Grey Magnetic Box
4.6Editor score
Two strong neodymium magnets
Air tight waterproof seal
Discreet undercarriage placement
Top 10 Best Magnetic Key Box for under Car in 2026 Compared
This side by side comparison highlights key differences across all ten models to help you make an informed decision based on your specific storage needs and vehicle type.
ProductsSpecificationsEditor scorePrice
Best Budget
Magnetic Key Box MM1 Regular
3.5 x 2.0 x 1.0 inches
Waterproof magnetic design
Standard key capacity
Portable undercarriage use
4.6Editor score
Editor's Choice
2 Hide A Key Magnetic Under Car Spare Key Holder
4 x 2 x 5/8 inches
Two premium quality magnets
Tough ABS case
Multi-use storage option
4.6Editor score
Best Premium
Large Magnetic Key Box for Under Car Fits Bulky Key Fobs
8.5 x 5.9 x 2.7 inches
Four magnet mounting
IPX5 weather protection
Fits bulky key fobs
4.3Editor score
Master Lock Magnetic Key Holder Black 207D
4.7 x 1.2 x 2.0 inches
Sliding cover design
Durable plastic body
Indoor or outdoor use
4.5Editor score
Magnetic Key Box for Under Car with Combination Lock Box
3.7 x 2.4 x 1.3 inches
Five strong magnets
Resettable combination lock
Includes waterproof bags
4.2Editor score
Magnetic Key Holder Under Car Weatherproof
4.6 x 2.8 x 1.5 inches
Two Neodymium magnets
Splash resistant latches
Removable interior padding
4.7Editor score
Upgraded Magnetic Key Holder Under Car with Padding
Compact sturdy design
Three Neodymium magnets
Soft cushion inside
Upgrade safety buckles
4.6Editor score
Nite Ize Hideout Magnetic Key Box Extra Large
Extra large capacity
IPX7 waterproof rating
Includes adhesive metal plate
Versatile storage solution
4.6Editor score
Magnetic Key Box with 3 Magnets
Three powerful magnets
Rugged ABS plastic
Waterproof weatherproof
Compact low profile
4.6Editor score
Hide a Key Outside with our Grey Magnetic Box
Two strong Neodymium magnets
Air tight design
Undercarriage placement
Gorilla Box branding
4.6Editor score
1. Magnetic Key Box for Under Car with Combination Lock Box – Best Security
Magnetic Key Box for Under Car with Combination Lock Box
Five strong magnets hold
Four digit combo lock
Soft sponge padding included
Ultra durable material build
This magnetic key box combines strong magnetic hold with a resettable combination lock for enhanced security. It holds spare keys and small valuables while resisting water and impact during travel. The unit earns a 4.2 star rating from users who value dual protection.
Pros
- Combination lock adds security
- Strong magnets prevent loss
- Includes waterproof bags
- Durable for long term use
- Good for trucks
Cons
- Resettable code may be tricky
- Slightly heavier design
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The five powerful magnets provide superior grip compared to single magnet models. This reduces the risk of dislodging over rough roads. The soft sponge pads inside protect keys from scratches and rattling during movement.
While the combination lock adds security, some users find resetting the code requires patience. The box is also slightly heavier than minimalist options, which may matter for minimalists but improves overall durability.
Buy this model if you need extra protection beyond magnets alone. It suits truck owners and fleet vehicles where security and durability are priorities. Always store keys in the included waterproof bags for maximum protection.
Enhanced Lock Security
The 4 digit resettable code ensures that only authorized users can open the box, reducing theft risk even if the magnet is spotted.
Internal Protection Features
Soft sponge pads and waterproof bags included in the package help keep keys dry and scratch free in harsh weather or off road conditions.
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2. Magnetic Key Box MM1 Regular – Best Value
Magnetic Key Box, Hide A Key Holder, Under Car Magnetic Key Storage
Waterproof hidden design
Super strong magnet hold
Portable under car use
Compact 3.5 inch size
This waterproof hidden key box offers reliable under car storage at a budget friendly price. Its compact size and strong magnets make it ideal for single spare keys. Users rate it 4.6 stars for value and practicality on daily commutes.
Pros
- Affordable pricing point
- Waterproof hidden key box
- Strong magnet attachment
- Compact size fits easily
- Reliable for travel
Cons
- Small interior space
- Basic plastic build
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The super strong magnet ensures secure attachment to ferrous surfaces even on bumpy roads. The waterproof design protects keys from rain or road spray during normal driving. Its portable dimensions fit easily under most vehicle chassis.
The interior space is limited to about 3.5 inches, so bulky fobs may not fit comfortably. The basic plastic body is durable but not ruggedized for extreme off road use.
Choose this model if you want a simple affordable solution for spare keys. It works well for daily drivers or light travel. Ensure your spare key is slim enough to avoid jamming the sliding cover.
Compact Convenience
The small 3.5 x 2.0 x 1.0 inch interior keeps the box discreet while still holding standard house or car keys easily.
Strong Magnetic Grip
High quality magnets hold the unit firmly to the chassis without rattling or detaching during high speed driving or uneven terrain.
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3. Hide a Key Outside Grey Magnetic Box – Best Seal
Hide a Key Outside with our Grey Magnetic Box
Two strong Neodymium magnets
Air tight waterproof seal
Undercarriage discreet placement
Reliable durable design
This air tight magnetic key box keeps keys dry and safe using two powerful Neodymium magnets. Its grey finish blends well under vehicles. Users praise its reliable seal and discreet look, giving it a 4.6 star rating overall.
Pros
- Air tight protection
- Strong Neodymium magnets
- Discreet grey finish
- Reliable for long term
- Easy access design
Cons
- Higher price point
- Limited size options
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The air tight design prevents moisture intrusion better than standard models. This is vital for coastal or rainy regions. The strong magnets stay secure even during high speed or rough road conditions.
The higher price reflects premium materials and sealing. Size options are limited compared to large capacity boxes. If you need to store multiple items, consider a larger model instead.
Invest in this box if moisture protection is your top concern. It suits coastal homes or frequent travelers. Verify the seal regularly after exposure to salt or heavy rain to maintain performance.
Waterproof Seal Performance
The air tight construction ensures that humidity and rainwater cannot enter, keeping keys dry and functional after heavy storms or washes.
Discreet Grey Finish
The grey exterior helps the box blend into vehicle undercarriages, reducing visual detection by passersby or casual observers.
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4. ALAZCO 2 Hide A Key – Best Multi Use
2 Hide A Key Magnetic Under Car Spare Key Holder
Large ABS case build
Two premium magnets
Jumbo 4 inch size
Multi-use storage option
This ALAZCO spare key holder features a large ABS case with two premium magnets for secure storage. It can hold keys, money, or tracking devices. Users rate it 4.6 stars for its versatility and robust construction.
Pros
- Large interior capacity
- Strong magnet attachment
- Durable ABS case
- Great for small valuables
- Easy open design
Cons
- Requires slide opening
- Heavier than slim boxes
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The jumbo size allows storage of bulky items beyond keys. The ABS case resists weather and impact well. Two magnets distribute force evenly to prevent tipping or sliding during movement.
The slide open mechanism requires firm pressure which may be tricky with wet hands. The case is heavier than compact options, which can add slight drag or risk on very smooth undercarriage panels.
Choose this if you need room for trackers or notes. It works well for RVs, boats, or offices. Ensure the sliding track stays clean to avoid jamming during high use periods.
Versatile Storage Space
The large 4 inch interior accommodates multiple keys, cash, notes, or small tracking devices for broader emergency use.
Dual Magnet Stability
Two premium quality magnets provide balanced force to keep the case flat and secure on steel surfaces during travel.
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5. Large Magnetic Key Box – Best for Fobs
Large Magnetic Key Box for Under Car Fits Bulky Key Fobs
Holds bulky key fobs
Four magnet mounting
IPX5 weather protection
8.5 x 5.9 x 2.7 size
This large key box is designed to fit bulky key fobs that smaller models cannot hold. It uses four magnets for stable mounting and includes IPX5 weather protection. Users appreciate its capacity and rate it 4.3 stars overall.
Pros
- Fits modern fobs
- Four magnet distribution
- IPX5 rain resistant
- Large 8.5 inch capacity
- Optional zip tie retention
Cons
- Large size visibility
- Seal inspection needed
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The spacious 8.5 inch housing holds multiple keys, cards, and trackers easily. Four magnets distribute holding force to prevent shifting. Latches and zip tie holes add optional security to prevent accidental opening.
Its large footprint may be more visible to thieves. The seal requires periodic inspection after heavy rain or mud exposure to ensure ongoing waterproof performance.
Buy this if your spare key includes a large fob. It suits trucks or fleet vehicles. Inspect the seal after severe weather to maintain the IPX5 protection level.
Large Capacity Design
The 8.5 x 5.9 x 2.7 inch housing holds bulky key fobs and multiple keys that standard boxes cannot fit.
Four Magnet Stability
Four magnets distribute holding force across the steel surface to prevent tipping or shifting even on rough roads.
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6. Master Lock 207D – Best Classic Model
Master Lock Magnetic Key Holder Black 207D
Sliding cover design
Durable plastic body
Small interior space
4.7 inch exterior size
Master Lock is a trusted brand for storage. This model features a sliding cover with built in stop to prevent loss. It is compact and durable but is not intended for use on cars per manufacturer guidance.
Pros
- Trusted brand
- Sliding cover safe
- Durable plastic build
- Compact size
- Indoor or outdoor use
Cons
- Not for cars per label
- Small key capacity
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The sliding cover mechanism is smooth and secure. The durable plastic body resists wear and weather. Its small interior fits 1 2 keys comfortably.
The label explicitly says not intended for use on cars. This limits its undercarriage reliability for vehicle storage. Users may still use it on other steel surfaces like sheds.
Choose this if you need a small non vehicle storage solution. For cars, pick a model explicitly rated for undercarriage use. Always verify manufacturer warnings before mounting on vehicles.
Sliding Cover Safety
The built in stop prevents the sliding cover from being dropped or misplaced during access.
Brand Reliability
Master Lock is a known name in security products, offering predictable build quality for basic key storage needs.
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7. Weatherproof Magnetic Key Box – Best Splash Resistance
Magnetic Key Holder Under Car Weatherproof
Splash resistant design
Two Neodymium magnets
Four strong latches
Removable interior padding
This magnetic key hider features strong Neodymium magnets and splash resistant latches. It earns a 4.7 star rating for reliability. The dark color and generous capacity make it practical for everyday use.
Pros
- High 4.7 rating
- Strong Neodymium magnets
- Splash resistant latches
- Large capacity fits fobs
- Padding prevents rattling
Cons
- Not fully waterproof
- Padding reduces space
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Two Neodymium magnets provide strong attachment to ferrous steel. The self aligning retainer ensures the box stays shut unless opened. Latches are simple but durable for repeated use.
It is splash resistant not fully waterproof, so submersion risks remain. Padding inside helps protect keys but reduces available space. Remove padding for maximum volume if needed.
Buy this for daily driving and light weather. It works well under cars or trucks. Place key fobs in a zip bag before mounting if driving through deep puddles or wet conditions.
Neodymium Magnet Strength
Two Neodymium magnets provide a separation force of 60 lbs, ensuring the box stays secure even at high speeds.
Internal Padding Options
Removable padding prevents rattling and protects items but can be removed to increase storage space as needed.
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8. Upgraded Magnetic Key Holder – Best Cushioning
Upgraded Magnetic Key Holder Under Car with Padding
Soft cushion interior
Three Neodymium magnets
Safety buckle design
Waterproof weatherproof build
This upgraded magnetic key box includes a soft cushion inside to protect valuables from rattling. It uses three Neodymium magnets and upgraded safety buckles. It is waterproof and weatherproof with a 4.6 star rating.
Pros
- Soft cushion inside
- Strong Neodymium magnets
- Safety buckle secure
- Waterproof weatherproof tested
- Removable cushion space
Cons
- Padding may limit space
- Slightly higher cost
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The soft cushion keeps keys and cards from scratching during travel. The safety buckles are designed to endure repeated bending without detachment. Three magnets ensure secure hold on steel frames.
The cushion reduces internal space but can be removed if needed. The cost is slightly higher than basic models. It remains a solid choice for regular under car storage.
Choose this if you value internal protection for keys. It suits SUVs or trucks with rough terrain. Remove the cushion if you need maximum space for larger items.
Internal Cushioning
The soft cushion inside prevents scratches and rattling of keys during travel across bumpy roads.
Upgraded Safety Buckles
Safety buckles are designed to withstand repeated opening and closing without detaching during regular use.
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9. Nite Ize Hideout XL – Best Waterproof
Nite Ize Hideout Magnetic Key Box Extra Large
IPX7 waterproof rating
Extra large capacity
Includes adhesive metal plate
Versatile storage option
This Nite Ize hideout is waterproof to IPX7 standards, protecting keys from submersion. It has extra large capacity and strong Neodymium magnets. Users value its versatility and warranty with a 4.6 star rating.
Pros
- IPX7 waterproof rating
- Extra large storage space
- Strong Neodymium magnets
- Includes adhesive plate
- Worry Free Guarantee
Cons
- Adhesive plate needed on non steel
- Higher cost
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The IPX7 rating means it can survive brief submersion. Neodymium magnets secure to any steel surface. The included adhesive metal plate allows mounting on wood or plastic too.
The higher price reflects robust waterproofing and warranty support. Using the adhesive plate may not be as strong as direct magnets on steel. For under car, direct magnets are preferred.
Invest in this if waterproofing is critical. It suits boats or extreme climates. On vehicles, use direct magnet contact on steel frames for best hold.
IPX7 Waterproof Rating
The IPX7 rating ensures contents stay dry even during brief submersion, ideal for flood zones or boat storage.
Adhesive Mount Option
The included 3M VHB adhesive backed metal plate allows mounting on non metal surfaces like wood or plastic.
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10. Triple Magnet Key Box – Best Hold
Magnetic Key Box with 3 Magnets
Three powerful magnets
Waterproof weatherproof seal
Rugged ABS plastic
Compact low profile
This key box features three powerful magnets for maximum hold on ferrous surfaces. It is waterproof and rugged for all weather use. Its compact profile keeps it discreet under vehicles with a 4.6 star rating.
Pros
- Three powerful magnets
- Waterproof weatherproof
- Rugged ABS plastic
- Compact low profile
- Easy install
Cons
- Standard size limit
- No combo lock
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The triple magnet design provides a stable attachment even on rough roads. The rugged ABS plastic resists corrosion and impact well. No tools are needed to install it.
It lacks a combination lock so theft relies solely on secrecy. The standard size may not fit bulky fobs. For most keys, it is reliable and easy to use.
Choose this for simple effective under car storage. It suits SUVs or trucks. Verify the magnet surface is clean and flat before mounting for best results.
Triple Magnet Hold
Three powerful magnets provide maximum strength hold on any ferrous surface including undercar frames.
Compact Low Profile
The compact low profile design ensures it won’t interfere with driving or become an eyesore under the vehicle.
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Buying Guide – How to Choose the Best Magnetic Key Box for under Car
Selecting the right box depends on your vehicle type, storage needs, and security priorities. This guide outlines key factors to consider before purchasing.
Magnetic Strength
Stronger magnets reduce the risk of the box dislodging during high speed or off road driving. Look for models using multiple Neodymium magnets rather than single weak magnets. Test the hold strength on a clean steel surface before regular use.
Strong magnets ensure the box stays secure on rough terrain or highways.
Weatherproof Rating
Waterproof or splash resistant designs protect keys from rain, mud, and road spray. Look for IPX5 or higher ratings if you drive in wet conditions. Ensure seals and latches are tight and intact.
A reliable weatherproof seal prevents moisture intrusion that can corrode metal keys.
Size Capacity
Choose a box that fits your spare key type without forcing. Bulky fobs require larger interiors while slim keys fit compact models. Measure your key dimensions before purchasing to avoid jams.
Correct size prevents key damage and ensures smooth access when needed.
Security Features
Some models include combination locks or zip tie holes for extra security beyond magnets. These add protection against visual detection or tampering. Consider if secrecy alone is enough for your risk level.
Extra security features deter casual thieves but rely on user discipline.
Mounting Surface
Ensure your undercarriage has a clean flat ferrous steel area for magnet attachment. Avoid placing on aluminum or rusted surfaces as magnets won't hold well. Clean the surface before installation for best adhesion.
Proper surface prep ensures reliable long term attachment and reduces loss risk.
Internal Protection
Look for soft padding or removable liners to protect keys from scratches and rattling. Padding helps maintain key condition over long use. Remove padding if you need more space for bulky items.
Internal padding preserves key condition and reduces noise during travel.
Build Material
ABS or durable plastic resists impact and corrosion better than thin shells. Check for reinforced latches and smooth covers that won't jam in extreme temperatures. Material quality affects longevity under the vehicle.
Rugged materials ensure the box survives daily driving conditions and weather.
Budget Value
Basic models offer good value for simple storage while premium units add waterproofing or locks. Balance cost with expected usage frequency and risk exposure. Don't overlook warranty and return policies when comparing prices.
Choosing a value model saves money while still meeting most everyday needs.
How to Use and Care for Your Magnetic Key Box for under Car
Clean the mounting surface on your vehicle's frame with a dry cloth to remove dust or rust. Place your spare key inside the box and close the lid securely. Press the box firmly against the steel area until you feel the magnet engage.
Check the hold by gently pulling the box before driving. Inspect seals and latches after rain or heavy road use. For waterproof models, rinse the exterior after exposure to salt or mud and dry before reattaching.
Recheck magnet hold periodically and tighten or replace if loose. If using zip tie holes, add a nylon strap for extra retention on long trips. Keep the interior dry and avoid placing wet keys inside to prevent corrosion.
Frequently Asked Questions
Will a magnetic key box hold on all car undercarriages?
Magnetic boxes only adhere securely to ferrous steel surfaces. Many modern cars use aluminum or composite under panels. Check your vehicle frame for steel before purchasing and clean the area for best magnet contact.
How strong should the magnets be for highway driving?
For highway speeds, choose models with multiple Neodymium magnets rated for at least 50 lbs separation force. Stronger magnets prevent dislodging from wind and road vibration. Test on a steel surface before mounting.
Are magnetic key boxes waterproof for heavy rain?
Most are splash resistant but not submersible. Models with IPX5 or higher ratings handle heavy rain and road spray. Always inspect seals regularly and consider using a zip bag inside for extra moisture protection.
What size keys fit inside the average magnetic box?
Standard house keys and small car fobs fit most compact boxes. Bulky smart fobs may need larger models rated for extra capacity. Measure your key dimensions before purchase to ensure proper fit.
Can I use a magnetic key box on aluminum frames?
No, magnets do not stick to aluminum. If your frame is non-steel, use zip tie holes or an adhesive metal plate to secure the box. Alternatively, choose a non-magnetic mounting solution compatible with your vehicle.
Do these boxes have combination locks for extra security?
Some models include resettable combination locks while others rely on secrecy alone. Boxes with locks add a second layer of security. Consider your risk level and budget before selecting a lock feature.
How often should I check the magnet attachment?
Inspect the box weekly or after long trips to ensure it remains secure. Check for rust or dirt on the mounting surface. Clean and reattach if the hold feels weaker than usual.
What if the box falls off while driving?
Use multiple magnets and secure with zip ties or a chain if allowed. Ensure the mounting surface is clean and flat. Always test the hold before regular use and monitor for signs of loosening over time.
Final Thoughts on Choosing the Best Magnetic Key Box for under Car
We highlighted ten magnetic key boxes for under car storage ranging from budget to premium models. Top picks include the combo lock box for security and the grey air tight box for waterproofing. Each option balances magnet strength and durability.
Prioritize magnetic strength and weatherproof rating based on your climate and driving habits. Ensure the size fits your keys and that the undercarriage surface is steel. Extra features like locks add security but cost more.
Product prices and availability can change frequently. Always check the current listing before purchase to confirm specs and delivery. Choose a model that fits your specific needs for secure, accessible key storage.