My father has, in addition to his '85 300D, a 1984 Buick Regal. This car had to have it's tranmission replaced at about 90K. Apparently in '84 GM offered 2 different size engines for that car, but the tranny was designed for the smaller of the 2. So naturally with my father's car having the bigger of the 2 engines, it killed the tranny. The car has a overdrive tranny which was pretty expensive to replace in the late 80's. Then at about 150K the original engine gave up. So his Buick is basicly the same age as his Benz but it's on it's second engine and tranny and the car still doesn't run right. The plastic bits and pieces in the interior have all broken. Of course the Buick didn't cost as much new as did his Benz when it was new. My father bought his Benz in '95. Your car has a inline six which is inherently a more durable engine then say a V-6. Also of course it's a MB straight six. Look at any other cars on the road that are 15+ years old. If it's a domestic it's probably in very sad shape. If it's a Japanese car it's probably smoking like crazy and the interiors are shot. Most cars running around that are that old are European.

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1999 MB SL500 (110,000 mi)
2004 Volvo V70 2.5T (220,000 mi)
2014 Tesla Model S 85 (136,000 mi)
MBCA member