I just did a search on them and they all seem to have the same problems. For example the wireing harnes, evap core, vacuum problems, and the amp.
Other then that as long as you stay away from an S600 are they really any more money to keep going then the W126 is? I mean the I am a W126 fan but they are no bargin to keep going parts prices seem to be about the same.
It seems to me if you buy a nice say mid 90's S320/420 with a new harness, evap core and a good maintaince history it will probably be a reasonable car to keep on the road. By MB standards anyway.
Also none of the problems seem to be to terrible $$$ wise at least for the diy. The evap core can probably be done in a long weekend or over a vacation. The wireing harness seems to be around $400 and can't take more then a day. The door close and trunk close assit problems are an optional fix. I look at that as a neat little feature that is nice while it lasts!

But vac problems tend to be a pita to find but cheap to fix. The amps I'll give them that I don't know what they cost but their probably not cheap. But how often do they break? Every 10 years? Other then that no one seems to have major driveline or suspension problems.
Am I wrong here?