When I was in high school (in the '50s), I had a pickup that I rigged up a model T coil connected to the pickup body. I had a push-button switch under the floor floor mat just in front of the driver seat and a ground strap hanging under the truck. When i pushed the button with my foot it would give a good jolt to anyone touching the truck from outside. I could also touch bumpers with another vehicle and electrify it also. It didn't take long for word to get around and no one would touch my truck while I was in it.