Workshop with youngtimer competence in the Rhine-Main area sought

Hello, we are recently proud owners of a V90 from 1997. The vehicle is actually great in shot, only a few small things should be directed. Since we are not a gifted screwdriver, we have turned to the next Volvo representative. To our great surprise they told us that the service for “so old vehicles(!)” can only be made limited, and you could not order spare parts for it. With the hint to get the parts at SKANDIX, we were sent away again. Therefore my question in the round: Where are we welcome with our V90 (960) for maintenance? I look forward to all tips concerning the Rhine-Main area, or everything around 80km from Offenbach. Best regards and already thanks for your inputs!