On the early 129's, look for rust on the bottom insides of the doors behind the rubber seal. It's the only hidden rust area on these vehicles. My 1991 SL300 with 105K miles has not been a money pit; the previous owners maintained it well. The vehicle does have a lot of "charactor"; i.e. , idiosyncrasies which you may love or hate. The six cyclinder is only adequately powered to get the car moving, but pulls hard when the revs come up. It gets decent gas mileage. I average in the low 20's. On the highway the six cruises smoothly at high speeds, with plenty of power and gets about 26 mpg. The SL300 comes with a 5 speed auto, the SL500 has a 4 speed. So, look for good maintenance, sound mechanics, and low visible wear and tear on the interior. Buy from a seller who loved this car.

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