wow stephan, you have been spotting lots of M3s lately... i havent seen that many around the downtown area in the past 2 or 3 weeks ... although i saw a lot back in april, may... i agree that C63s have a nice mean sound to them. if the m3 had an exhaust like that, i wouldnt have to switch out my mufflers.
Current: 2013 F10 M5 & 2013 GLK350
997.1 GT3RS (gone)
2009 WRX STI (gone)
e92 M3 (gone)