I really don't know the car, so I can only tell you from my experiece on the '560 SEL I have. One thing we have in common is that my car's problems where there at purchase, and it had the same mileage as yours when I bought it - 97k.
The problems are gone now. I did the work myself...
1989 560 SEL (black/black)
2001 Audi TT Roadster (silver/grey)