Sounds a lot like my LSU games! I take my M3 to the games, never had an issue. In fact I parked near a pre-LCI E92 M3 a couple of weeks ago...
As with any situation, you try to be careful about where you park. Don't squeeze into a tight spot which will get you a door ding, look for end spots if possible (usually not!). Ultimately it is a car, my daily driver. Sh#t is going to happen no matter how hard you try to protect the car...
Current: 2011 Space Grey E90 M3, DCT, Comp. Pkg., Conv. Pkg., everything but Cold Weather Pkg!
Gone: 2008 550, Space Grey, Sports Package, Sport Auto Transmission.
Sold: 2004 545i (U.S.), Steptronic, Silver Gray.