Took the car in because it was blowing oil around the lid of the oil filter. BMW said it was a broken 'O' ring. I had the oil changed and filter replaced. BMW completely cleaned all the blown oil out of my engine compartment (kudos for that). However during my recent two days on the track I noticed that I was still blowing oil around the filter lid. On close inspection it was obvious that the filter lid was not making full contact with the filter base at one point around the circumference. I now have an engins compartment fouled with blown oil for BMW to clean again. MAKE THEM CLEAN YOUR ENGINE!