i ordered 2 cables off ebay, one is a male to female and a smaller male end one with a headphone jack on the end, when i unplug the larger harness and just plug the "input" side of the plug in to the back of the radio, the factory amp dont turn on im guessing cause no sound.. so the male to female took care of that. but now the cd changer is not connected so the head unit does not recognize it being on so no way to use the aux input cable..

here is the cables i have, car is a 2001 a4 with symphony sound and trunk mounted changer





so imagine the blue, green and yellow connectors put together as one is what comes from the car into the deck, now it goes into the red female end and those 3 color ones go into the deck fine, cd and radio work, no changer so i cant use the headphone jack input..

also, these connectors costed me only $24 shipped for both so no big deal but i still hope they can work