OK guys...went over to my Indy's place and checked out the 88 420SEL. It is absolutely immaculate. Drives like a dream, burgundy paint is shiny, new palomino leather on the front seats (seat covers from the factory replaced the old ones), no leaks visible on the engine, and everything works like it was new...took it out on the interstate and it's got plenty of get up and go, cruise control works, both power seats work, power antenna works, and my wife noted that (unlike the 300TD) when you turn the key off, it stops. My Indy has been taking care of it since 1993, and has all the records to prove it including all major and minor maintenance, oil changes, tires, fluids, etc. Tranny was rebuilt at 218,000, and he said the timing chain is in like new condition.
Owner is adamant that she wants $5500, although KBB says retail is more like $3600. I'm inclined to think that the excellent maintenance and cosmetics count for quite a bit. SWMBO likes it and thinks it's worth it. Any thoughts? Royce Engler '85 300TD 298K