Hi, I bought an original ipod interface for my Audi A3. its a 2009 model with a chorus radio. I plugged it in using the quadlock. Then there is a brown wire on the quadlock cable. The instructions say unplug the brown wire from the back of the radio and put the brown wire from the interface into the back of the radio. Only thing is on my radio there is no brown wire. Not sure if i used the correct wire. The interface works but it is not charging the ipod. Plays well though. Any ideas or help would be greatly appreciated. Brendan.