About 1000 kms after my dealer upgraded my M3W to stage 1, after crossing the "Grossglockner Alpine Street" having a lot of fun, at the Hotel in the evening I discovered cracks very similar to your cracks. My dealer did not bother waiting for the factory reaction, he welded both sides - no problem since!
Karl, did he just weld where the cracks were around the pipes and muffler cans, or did he add any reinforcement gussets?
