As I search for parts, I find that some are compatible and others not, and the only difference is the class. Example, a GPS antenna; Base and Elite is OK, but not for the Luxury, Why?
MBFanatic 3 months ago
Most parts on the A6 are interchangable as you mentioned but not everything. The head unit on the luxury A6 may be made from a different manufacturer than the base model. Yeah, Audi does outsource the small components. On the Base the head unit may be made by Bosch and the Luxury by Harman Kardon.
With that said, another factor is the production date. Even the month the vehcile was manufactured make a difference.
What I would do is to find the part number of whatever part you are looking for. Most car parts stores or Audi dealer can help you with that. Or if you have the old part removed, it is stamped on the part itself.
Use that part number to find a used one. Then you don't have to worry if the part works with your car or not. Another thing that you may find is that the part you may be looking for could have been used on an 2010 Audi A4 as well.
Good luck with your search. Hope this helped.