One problem related to manifold/header/muffler/tail pipe has been reported for the 2011 Porsche 911 Gt3. The most recently reported issues are listed below.
Due to well-documented issues with glued coolant tubes failing and resultant loss of coolant over rear tires which would almost certainly make control of the vehicle impossible in the "gt1"-engined Porsche models, I had the coolant tubes welded to the coolant manifold of the engine at my expense at my local Porsche dealer to prevent the failure from occuring. I strongly feel that this known failure mode should be covered by a NHTSA recall and the cost of the repair should be borne by Porsche. Sincerely, david palmer.