$21K sure sounds low for an 04. Definately check Edmunds and KBB, but also search completed auctions on Ebay and asking prices at some of the online spots such as traderonline.

Sounds like this car has airmatic. I'd expect the rear suspension setup is completely different than the older wagons. Through the 210 chassis the wagon used the same basic self leveling design in back with hydraulic struts, accumulators, level control valve, and springs. Same setup as your 560. Not sure what MB implemented on the 211 wagon.

- JimY