Mate, you probably don't want to hear this, but don't forget that your car may not have been randomly targetted. I'm not saying anyone deserves to have that done to their car, but you can't just blame it on the fact you have a nice car. Maybe you acted like a dick to the wrong person and they took it badly.
I'm saying this because I drove my car to college almost eveyday at the end of year 12. I had people walking past it everyday, staring in the windows and stuff, but i never had any problems with people keying it or doing anything stupid. Might be food for thought...