The third layer of protection is a device which prevents thieves from bypassing your ignition and hot wiring the vehicle. Some electronic devices have computer chips in ignition keys. Others inhibit the flow of electricity or fuel to the engine until a hidden switch or button is activated. A third category passively immobilizes the vehicle by interrupting the starter, ignition or fuel. The final layer of protection is a tracking system which emits a signal to a police or monitoring station when the vehicle is reported stolen.
Tracking systems are very effective in helping recover stolen vehicles.