I hate to say it Jeff, but an alarm will not solve your problem. The problem is that you drive a car that gets a lot of attention: small, cute, and drunk macho guys hate it. You add to the fact that the car is around thousands of college students and you get a recipe for disaster. I know when I was young and dumb and went to the U, I once threw a couch off of the 5th floor of our dormitory because it was cool and I wanted to test the laws of physics.
Well I'm sure these college students wanted to test their physics theories on this car as well.
I hope students respect your property, but I'm guessing that the next prank might involve your car being put on top of a tree.
Good luck!