30k intervals are too long imo. I keep a 10.000 km interval on mine. It's been running pretty darn well, but right now it is sitting idle because my valvetronic is causing problems (again for the second time in like 3 months, car doesn't start, seems to be an electrical/wiring/sensor issue). Other than that it is a great machine, mine has "only" 170.000 km though, and it's been well maintained for the last 6 years (since I bought it). I guess the older they get, the more problems will probably occur. Impossible to tell how the cars have been driven, so I guess you'll always be buying the pig in the poke with these cars.
In general, buying from northern Germany should be better with regards to wear and tear on the body because there is much less snow and salt being sprayed than say Bavaria.