Owned a 1994 W140 S600 for 8 months and i've just finished a major work on the ADS suspensions. The PO is change the oem ADS suss with a non ADS susspension unit, and to going back to an oem spec i've to change the power steering pump, ADS control unit, shocks,sensor, balls, hoses, brackets etc.
The cost for the parts for this job is approx 6K+ USD )-:
Other parts i've changed is all the fluids (motor oil,atf,radiator coolant,power steering fluid), filters, front seatbelts, Front orthopedic seats ballons,3 power window motors, engine mountings, several switches, electric roller blinds motor etc
After all i've done to the car , i'm still in love and hate situation with the car
Love to drive it but hate to see the mechs coming