bummer man,
*Might I suggest running a cable with a standard 3 prong plug on one end and a large crocodile clip attached to the other.
Attach c/clip to chassis then plug in socket, prefferably keep car on your drive way, turn on switch and you have a pretty good vandal deterrent.
If someone touches the car, fizzz. 240v through whatever touches the car first

Disclaimer* Deeply illegal and wouldn't recommend you try this at home.