Well if you arent able to do anything to him physically then just be sure to catch him doing shit to your car. If things get severe enough, just get a police report and take it to small claims court. On the side note though, he seems like he really hates you? Why are you letting him push you around like that? I go to high school as well and if i saw a dumb kid trying to do anything to my car i'd either pound his ass or call the cops to file a report then start pounding his ass. Either way, bloodshed would be neccessary for revenge.
Peanut Butter Chunky