I am very pleased with my 2009 C4S performance but remain very concerned about how it literally "drinks" oil and the soot that accumulates on the exhaust. Is anyone else experiencing these problems? Is this "normal"? The dealership says yes, but my intuition tells me any vehicle you pay $117k should not do this. What is the real deal here? Should I keep data on mileage and how much oil this car is consuming for any potential unknowns yet to be discovered because this a "new", unproven model. Help!