bologna on the paint, banana in the tailpipe(s), and chocks under the front tires. if he has a runner board on his truck, put grease, oil, or vasiline on it so when he steps on he slips and smashes his face, loosen the radiator cap, those are just the ideas off the top of my head that could happen to him if he were to really cross someone.
*wink, wink, nudge, nudge, say no more, say no more* (yes i added a shameless monty python plug)