Report of cars being started in a way that "bypasses the ignition system" I think they probably mean that it acts like a substitute key fob, but that video isn't exactly big on details. Anyway, it got me thinking. Many places where one might place a kill switch would cause big problems if the added circuit failed while driving. For instance, a kill switch in the power wire going to the fuel pump - if that added switch or wiring fails on the highway it will be, exciting. So what I'm wondering is how one might wire a kill switch in for a Prius so that it only disables starting the car. I guess that makes it more of an enable switch than a kill switch. There is a simple way to almost do that. Cut into the wire from the start switch and add a momentary switch to restore that connection. Then the car only starts if that new switch is pressed at the same time as the start switch. Unfortunately it doesn't quite meet the desired goal, because both the added switch and the start button must also be pressed simultaneously to turn the car off. It is also attached in a very obvious place, and a skilled thief might know to check the wires near that button for modifications. If there is just a simple switch there they can jumper around it, or cut it out and twist the wires together, either way quickly removing the modification. Bonus points if the modification honks the horn when the start button is pressed without also pressing the kill switch. But again, only when starting the vehicle.
