I thank the OP of this thread the most for the video illustrating the difference between exhausts of the M3's. One with the M Performance Exhaust and one with the stock exhaust. I knew the stock sounded good from outside the car but I had no idea it sounded that good at WOT. After hearing that there is no longer an urgency to upgrade IMO. The M Performance did sound better but not $3k better.
"what I'm driving here...is an ending." Jeremy Clarkson
2010 Carrara White Porsche Cayman 6mt
2014 Whiteout Toyota GT-86 6mt(Sold 05/23/15)
2011 Alpine White BMW M3 6mt ZCP Coupe(forced retirement 06/06/14)
2008 Alpine White BMW 328i 6mt Coupe(retired 06/21/11)