The early 140's were plagued with problems. I purchased a new 1992 500SEL. It was a nightmare to say the least, had to my estimation OVER $20,000 worth of warranty repairs the two years I owned it. It is my understanding that many of the items can bu updated and improved. But I would NEVER own one without an extended warranty. I recently sold my 1996 S500. It was significantly less troublesome than the 1992.
To make a correction on what the "DOC" stated above: The class-action lawsuit was for the "front-end shake" the 1992-93 models exprienced. In 1992 and 1993 ALL S-Class models came STANDARD with a 4/50 maintenance agreement. I have never heard or known anyone to receive any "maintenance agreement" AFTER the fact, it certainly wasn't part of the class-action settlement. that I know of.