The steering shimmey is fixable if the tech knows how to do the repair. The 140's have updated the stiffness of the lower control arm bushings and the ball joints. After the repair the vibration is gone.
I like the 500. It seems to be a good car. Always go with the year after the introduction of the car (92). Also be sure that the evaporator is OK.

------------------
Benzmac:
ASE CERTIFIED MASTER AUTO TECHNICIAN
LEAD TECHNICIAN FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM