Chances are it was probably random. My car got keyed after only owning it for 4 days…no one even knew it was mine. There are scumbags out there that see that its a nice car with temp plates or temp registration and get jealous that their life sucks so they do it to bring you down. My buddies BMW has been broken into, and someone punched in the fender (yes punched) both times he left it on the street downtown overnight. Shit like that is bound to happen with all the low lifes and drunks walking around those areas.
It sucks, but unfortunately theres not much you can do about it… thats what you have insurance for and why you have to pay higher rates when you live in the city. Same stuff happened even when I drove my Grand Prix… and I dont think I have that many people who hate me… haha.