Car Keyless Entry - A remote keyless entry system for a car is a system designed to remotely permit or deny access to the premise or to your automobile. A remote keyless system can include both a remote keyless entry system, or an RKE, and a remote keyless ignition system, or a RKI. Remote keyless entry systems for cars operate by broadcasting radio waves on a particular frequency. Most RKEs work on 315MHz in North America and Japan, and 433.92MHz in Europe. Modern systems implement encryption to prevent car thieves from intercepting or tricking the signal. The system signals that it has either locked or unlocked the car through a combination of different features, including flashing vehicle lights, a distinctive sound other than the horn, or some usage of the horn itself. The functions of a remote keyless entry system for a car are contained on a key fob or built into the ignition key handle itself. Buttons on the keyless entry system are dedicated to locking or unlocking the doors and opening the trunk, or, on sport utility vehicles and station wagons, it can unlock or open the rear tailgate. Some cars will also close any open windows and sunroof when remotely locking the car. Some remote keyless fobs also feature a red panic button which activates the car alarm when pressed. Some cars' engines with remote keyless ignition systems can be started by the push of a button on key fob.