considering purchasing'00 323, noticed sell of oil after car has been driven

Hard to say with out being able to drive the car or inspect to see if oil is getting on the exhaust. Are you buying the car from that dealer or from a private party. Have a pre-purchase inspection done by a garage knowledgeable in BMW, it will be money well spent, what they find may divert you from buying a "bad car" and or what they find (lack of maintenance or repairs needed) can be used to negotiate price.

Valve cover gasket is the big problem with this car.Had mine replaced twice.I have 295,000 miles on it and runs great.Great car!!!!