OP. Just search the 3-series forum for exploding sunroof. You'll find several examples. If I were you, I would print out several of the photos that were posted along with some of the posts. Bring this information to the dealership with you when you talk to them. This way you can show that it has happened to other BMWs. Hopefully, this will help in getting the warranty to cover the failure. See the below link for several examples.
http://www.e90post.com/forums/showth...loding+sunroof
Leif W