An electronic system for preventing keys from being locked inside a vehicle. An ignition or door key houses a wireless transmitter which can send a signal to lock or unlock the vehicle doors. As a driver approaches a locked car, the unlock button on the transmitter is pressed, thereby unlocking the doors....http://www.google.fr/patents/US5600302?utm_source=gb-gplus-shareBrevet US5600302 - Vehicle-based anti-lockout system
