If you want to Live up you Car body, use an electric fence transformer. These Pulse 7000VDC, enough to shock, but wont "hook" a person up and kill them. But I would say you would have to isolate evey thing electrical in your car from the chassis in order to stop things being fried.
Also, better get your alarm installed right, for somone just to pop the bonnet and cut wires to alarm, is pretty useless install, even if it is 5 star.
A 1star alarm installed right is better than 5 star installed half arsed.