Just a small rant: I suffered from this same issue of broken bolts but it caused a little more damage. I drop my car off at the dealer over the weekend and came today (monday) to talk with the service advisor. Its seems the damage according to BMW is faily large, $10,000 large, diff, subframe, exhaust shields, bolts, and driveshaft. The dealer basically told me that the car is not meant to be beaten and that they will pull the log, and that it may or may not be covered by warranty. Now I'm pretty scared that this is not going to be covered as there was little to no assurance of what will be happening. The funniest part about this is a few weeks ago I heard a loud thud from the diff and decided the bring the car in for a check-up as the subframe was also rusted. The dealership told me that everything was normal and even rust was normal, they just put some paint to clean it up. Its a BMW certified 2008 m3 6speed with 20k miles, never winter driven and from the looks babied by previous owner.
I have had some track time on the car of maybe about 20-30mintes and I wasn't really beating the car. I've launched it a few times but never above 3500rpm, and I figure a DCT you can launch at 4000-6000rpm, then 3500rpm I'm in the safe zone. The dealer said they never seen this before which I do believe but it seems fairly common on these boards.