I finally tore into the rear of my W124 and found the LCAs were completely deteriorated. They were so loose and all the rubber was missing. I changed them and I swear the rear of the car is higher and it no longer wanders while I am driving on the highway. I still wish it rode as smooth as my wife's Acura, but I guess it is not fair to expect a 25 year old vehicle to ride like a 10 year old vehicle.

__________________
1987 Mercedes 260E (W124) 213,000 miles
1971 MB 220 w/ 4 spd manual (W115) "Suzy" (sold)