Just remember the old saying "Revenge is a dish best served cold." Don't do anything for a while. Take all the legal course of actions first and get your ride fixed. Give him plenty of time to forget about what he did. That way when someone (not you or course, you would never do something like that) totally F's up his ride, you're not the only suspect. I'm sure that a jackass like him makes plenty of enemies, so give him time to forget about you. On a totally different subject, I've been told that you can buy large craft sponges, cut them into letters to spell something really bad, soak them in brake fluid and leave them on his hood. I hear that it works pretty good and he'll be stuck with your message on his car until he gets it painted.