Faults:
Speedometer/Odometer failure right after purchase, which was a 1000k repair.
Minor oil leak coming from valve gasket. This is an inherent weakness in this automobile. My independent MBZ mechanic says that the right side usually fails more than the left. I've had both right and left gaskets replaced.
Rear tires need frequent replacement. This is normal for this type of car. Alignments etc should be done by a certified MBZ mechanic.
Most repairs for this car have been routine, and were caught during routine service. I really recommend keeping these cars maintained and finding a good certified independent MBZ mechanic.
General Comments:
These are beautiful automobiles who command a great deal of attention and comments. I am routinely told what a beautiful Benz I have.
The car is powerful, sporty and a lot of fun to drive. When the suspension is placed in sport mode, the ride can be a bit stiff, but very responsive.
The COMMAND system is outdated, and cumbersome to use, but the stereo is an 18 speaker Bose which sounds impeccable. It has several sound settings that help make the listening experience more enjoyable.
I love having the shiftronic transmission. Often the car has a lag in downshifting if I allow the car to do it on it's own. With shiftronic, a simple tap to the stick brings an immediate downshift or upshift. The car will not allow you to downshift if the RPMs are too high so you won't damage the engine.
Excellent brakes, especially on wet pavement.
Built like a tank, although I wish the interior were just a bit quieter (a little road noise can intrude into the cabin).
The leather is a disappointment, I have placed custom sheepskin pelts on the front bucket seats to limit wear to the leather.
There are a few rattles and squeaks here and there, but no more than I would expect from any 11 year old car.
I would advise that the cars need to be maintained religiously for best performance. Do your homework and find a good independent mechanic you can trust, and who won't rip you off. These cars ARE expensive to maintain. This is something you need to keep in mind before purchasing. They are imports, parts are not cheap, and labor to repair will not be cheap.
Gas mileage is decent for a car of this weight, and engine size (18 mixed driving, 23 to 26 highway. I've gotten as much as 28 on long road trips).
Overall, great value for the money, I think it will last a long time. I am sold on the Mercedes Benz nameplate, and am currently looking for a used convertible to add to my stable.