My friend lived for the past three years in one of the worst neighborhoods in Richmond VA - a city with very high crime rates. He parked his 245 on the street all that time and the only time anyone messed with his car was when his roommate stole his hubcaps as a joke.

If you install any kind of security system or kill switch in your car, it will only be for bragging rights. Nobody wants your car. They might break out the window and steal your stereo or other visible valuables, but the car is almost worthless to a thief.

If you have to do it, use a stock switch, like a seat heater, and hook it up to the start inhibitor circuit (NSS) or fuel pump relay. A car thief might look very carefully for a hidden kill switch, but how many are going to flip every switch on the dash to see what it does?