I own a 90 300E 4matic sedan not wagon. In my opinion if your into mercedes especially the older ones and don't mind doing brakes and parts due to age such as center drive shaft support and flexjoints then the car is pretty solid. The transfer case is problematic due to a seal that leaks hydraulic fluid into transmission i am not the first. The actualy 4matic system works very well in the snow with a nice set of snow tires. The transmission is solid only reason mine went was because of hydraulic fluid leaked in ended up rebuilding transfer case and transmission ever since works and shifts great. My main thing was the front sway bar bushings are garbage they wear out quick so i machined an insert for the swaybar instead of getting new ones from mercedes, also the the CV boots, u should only use mercedes boots i tried a off brand and not worth it. Also scheduled maintainence should be made on the car for the differential and transfer case fluids etc should be done when told. But for a car with 20 years and +200,000mi its not that bad , still haven't invested enough to compensate for buying a 30,000 new car with check engine lights on all the time and made of coke cans.