Why Wrapping Your Car Keys in Aluminum Foil Might Save You Thousands
Modern cars often use keyless entry and keyless ignition systems, which rely on radio frequency identification (RFID) or key fob signals.
When you press the button on your key fob or approach your car, it sends a signal to unlock or start your vehicle.
While convenient, this technology has a hidden risk: relay theft.
Relay theft occurs when thieves use a device to capture and amplify the signal from your key fob—even if the key is inside your house—and trick your car into thinking the key is nearby.
The car unlocks, and in some cases, they can even start the engine, allowing them to steal your vehicle within minutes.
Wrapping your key fob in aluminum foil acts as a Faraday cage, a simple barrier that blocks electromagnetic signals from escaping.
By doing this:
- No signal can reach the thieves’ devices – The key fob becomes invisible to the relay tools used to amplify the signal.
- Your car remains secure – Without receiving the key’s signal, your car cannot be unlocked or started remotely.
- Prevents costly theft – Modern vehicles can be very expensive to replace, and insurance claims can be costly or sometimes limited for high-end or new models.
Some people even use specialized Faraday pouches or boxes for the same purpose, but aluminum foil is an easy, inexpensive, and surprisingly effective DIY solution.
In short: By wrapping your key fob in aluminum foil, you can block unauthorized signals, prevent relay theft, and potentially save thousands of dollars in car theft losses.