Today I was in need of roadside assitance. I was towed to the closest BMW dealer and was told that they had to remove the above parts and clean them for carbon buildup. I was shocked to hear this as I always run Premium Gas and change the plugs. I had to shell out $375. Does anybody know of any recalls or advisories that might pertain to this problem? Does this charge seem fair for 3 hours of labor to diagnose and repair?