 Same issues: old CLS 550 @ $13,999 after the price drop of $5,000 had typical MB smell and the noise in the rear differential on the top. It will probably cost anywhere between $5,000 and $8,000 to replace the differential. Great start. Make sure you are driving your car with the radio OFF. Performance: it feels like MB 240 V-4 (not even V-6). Engine woke up for a few seconds at 60 mph but you are in traffic  in Virginia... and car is no different than Ford Crown Victoria. Mine had yellowish interior that smelled like MB "cabbage with gasoline".  Next day I drove Lexus LS430 @ $12,500 and I bought this car. Try both these cars before you make your decision. This is not about the price. Thank you.