I love mine, and haven't had one major problem with it since I received it back in August. Only regular oil changes, a little grease to the throttle linkage, a new $2 headlight knob (the old one would come off when you tried to pull it out to activate the fog lights), and a good car wash is all it has needed. Runs great, great mileage (best was 35.5mpg driving from Tacoma to Mt. Rainier and back), and pretty quick once it's up there. A little slow off the line (but pretty much any pre-CDI MB diesel is), but I'm coming off my dad's Volvo S70 turbo (191hp), so I was a little biased when I first drove it. Very smooth ride, and pretty good handling for a car of it's size and weight. The difference in ride quality between the Volvo and the MB were night and day. I drove the Volvo when the 300D was in for an oil change, and it felt like I was riding in the proverbial lumberwagon compared to the MB. But you do have to account for the fact that the Volvo is more of a sport sedan than the diesel MB is, so the Volvo's ride will naturally be stiffer. I like the supportive seats; some people definately have differing opinions on this, I'd drive it for a while if you can before you buy it to see if you like them. The stock radio is pretty good, and considering it was made in 1990 and is aging, it's excellent. Compared to the Volvo, the brakes felt a little under-engineered, but then again some say Volvo brakes are some of the best in the business, so I might be spoiled. Once you get used to them they're fine.
I love all the little features MB thought of when they designed this car. For example, if your sunroof motor dies, there's a little bolt in the trunk you can turn that will close it so your car doesn't get drenched when it rains.
The only things that don't work on my car are the cruise control (can get annoying at times), and the fuel guage sender (when it gets below 1/4 tank it goes to "R".) I can live with these, since I'm afraid to ask how much fixing the cruise control will cost
