2010 4.2 MT, Daytona Gray/Oxygen over Tuscan
You must have an old head unit then, If it has a media button rather than a TV button it "should work". Not sure I'd trust the dealers view on how our cars work. Part number for the adapter is in the manual from memory and I've personally seen it working in the TTRS (same head unit).
I've done some digging around online (google, ebay, amazon) and haven't found any place to source the "Bluetooth adapter for Audi Music Interface". Is the only likely place to get them from an Audi dealer directly?