My car is a 2002 C230K with the six speed trans. The car is driven fast but not hard and has 20,000 miles. The rear tires are worn down to their last 25% while the front tires appear almost new. Both front and both rear tires are wearing evenly, so alignment and balance are not an issue. I am an ex-autocross champ and so understand the importance of proper pressure, etc., and usually get 50,000 miles from a set of tires. Any ideas as to why the rear tires are wearing so fast? The average age of the two drivers is 55, so non-ESP burnouts is not the answer! Thanks.