[john70t]

Why you should wrap your keys in aluminum foil | Fox News
Always-on key fobs present a serious weakness in your car's security. As long as your keys are in range, anyone can open the car and the system will think it's you. That's why newer car models won't unlock until the key fob is within a foot of them.

But for less than $100, criminals can get an amplifier that detects key fob signals from up to 300 feet away and then transmits them to your car. In other words, your keys could be in your house, and criminals could walk up to your car and open it. This isn't just a theory; it's actually happening.