Has anyone replaced the valve cover gasket on their M5? I have some oil collected on both sides in the spark plug recessed area. Per this board, the claim is that the valve covers are leaking. As I am a DIY, I want to do this myself. I have the Bentley E39 book and on the 4.4 it seems faily easy although it doesn't really give great instructions. Looking for someone who may have done it themselves and can provide some tips. The car is still under warrantee, but I doubt that the gaskets are covered.