Just purchased a 2000 a6. It has 88000 and runs great. I notice an oil smell and took it back to the dealer where I made the purchase. They said the problem was a loose filter. When I test drove there was no smells of oil, but since the dealer did the oil change, there has been the oil smell. It no longer comes into the cabin, but when I get out after driving, there is the smell of oil. Anyone have any suggestions?