Rust or no rust? Too little information. Pictures? Check out the
buyers guide at www.mbcoupes.com for some issues to consider.

Are there records and books with the car? If so look through them carefully, to get a good sense of whether the car has been kept up.

Every 100k the car should get a new timing chain, tensioner and guide rail.
If it hasn't been done on this car, and you want it, you are overdue, way overdue and on borrowed time. If the timing chain jumps the rail, you can grenade the engine. With care the transmission should last 250k without trouble.

If there are no records and you still decide you want to buy it, it might pay to start a baseline maintenance program with new oil, p/s fluid, ATF and coolant, maybe even diff fluid, and flush the brake fluid, lube the sunroof track rails. Might need new motor mounts too.

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1991 560 SEC AMG, 199k <---- 300 hp 10:1 ECE euro HV ...

1995 E 420, 170k "The Red Plum" (sold)

2015 BMW 535i xdrive awd Stage 1 DINAN, 6k, <----364 hp

1967 Mercury Cougar, 49k

2013 Jaguar XF, 20k <----340 hp Supercharged, All Wheel Drive (sold)