My D3 has a connection for iPod, USB, composite (white and red RCA plugs) in the glove box next to the changer. On the MMI it gives me a lift of iPod, USB, Aux and some others. What can I play via the USB? What is AUX? It seems to be counting but nothing is plugged in. I'm at the in-laws at the moment, I'm going to borrow their iPod and see what happens.