I have been half-heartedly shopping around looking at the current Mercedes diesel market. I have noticed the W140 diesels seem to be rather affordable. Are these cars to avoid? I see that they have the 3.5L engine, is this the engine to avoid? When I graduate from college in May, I will looking for a diesel. I really like the W124 diesels. What of the newer diesels are the good ones, and what are the ones to avoid?