May I offer a radical suggestion to this question proposed. Go to Benzworld and ask the SLK people about reliability. This is NOT your typical Chrysler or your typical american made car. The mechanical compoents are Mercedes. Go to the Mercedes people they have a history with our car's underpining.

That being said I also believe it depends on how the car was driven, serviced and taken car of. I drive my cars for over 250,000 to 300,000 miles without major problems but then again they get great service and are driven with care. I do not believe mileage by itself is a measure of the car's value.