My 2006 Audi A6 has a std Bose CD AM/FM Audio system that now refuses to play AM radio?! I figured the radio was bad and managed to find a similarreplacement Bose system. Audi dealer installed the replacement system (after $100 to obtain the code numbers from Germany) and still the same lack of AM radio. Dealer told me it may be the AM antennae running from the unit through the back of the car. Part cost is $12, labor cost $500!! Does anyone know if/how the A6 rear internal antennae assembly (no external antennae on this model) can be repaired/investigated rather than an overly expensive AM antennae. Thanks in advance for the help.