If you are talking about tramlining, check you tyre pressure. In my case it was the culprit. I had put wider tyres in the E46 M3 - in fact it was CSL wheels on a normal M3 - and it was tramlining. Can't remembers whether increasing or decreasing fix it. No such issues with the E92 to date.
E92 M3 2007 - ///PE with Test Pipes and BPM Stage II; CF Interior & Splitters; CIC with Connected Drive