I feel the need to chime in here. Other than the ACC problem I'm having(which may be from using rebuilt rather than new parts) My 1984 300SD and 380SL have given me a minimum of problems.
The SD has had a new water pump, alternator, A/C compressor and battery. That's it except for regular maintainance (brakes, oil changes, etc).
The SL has had to have a new starter, water pump, timing chain and battery.
Both have over 100K on the clock.
By comparison the Cadillac Fleetwood that I used to own had ( in the span of 3 years) 3 water pumps, 2 alternators, 2 ac compressors a power steering pump
and more fuel pumps than you could put in the trunk (a little exageration).
I'll keep my Mercedes thank you very much