I'm waiting for my new 99 M3 Conv, and it can't get here fast enough! That aside, I've been reading through your message board and am now considering some performance enhancements like chip software upgrade, Cone filter, etc.
Before I did anything, I spoke with the dealership to see what changes could be made without losing my warranty.
Well, they said if they (the dealership) do the Chip upgrade, my warranty is fine. Otherwise, I risk losing my warranty. When I asked what chip upgrade they use, they mentioned Dinan. Judging from all I've read here, Dinan isn't what any of you would recommend. It seems you like the Jim C chip upgrade.
Have any of you dealt with the warranty issue of having the dealership make the modifications for you?
What's been your experience?