If you want to watch an impressive video this takes some beating:
http://video.google.com/videoplay?docid ... 7458424752
It's Hans Joachim Stuck driving a M3 GTR in 2004 in the Nurburgring 24hr race. It was running a prototype 4L V8 (now seen in the current E92 M2), revving to 10,000rpm. He was racing an Audi R8 V10 in last weekends Nurburgring 24hr race.