I have a 2005 Audi A6 and for some time the mmi has not been workin. the radio does not work and the screen does not come on when you start the car. the dealer said it would cost $1900 to fix. 1400 for the part and $500 for labor. the part is the interface module behind the glovebox. I found a similar part online which comes from an a8, but is supposibly compatible with the part I need and is only $250. so will the dealer be able to take this part and be able to get the mmi system working, or do I need to get the $1400 part?