Does anyone have an issue with the exhaust tips getting black with what appears to be carbon. For some reason, every two weeks mine are black and need cleaning - to me the engine must be running rich - there should be no carbon as the car is primarily highway driven?

 

 

Its very common and normal for some exhaust soot to stick to the tailpipe finishers. Mine need to be rubbed with some metal polish about once a month.

 

If it's not too bad, Windex on a rag will remove it. Takes about 5 seconds after every car wash. They still look new.

 

Not nearly as bad as my old 3GS.