ive fitted a twin sub and amp but i didnt touch the head unit i run the line out convertor off the speaker wires running to the little sub that came with the sporting style pack worked a treat and fitted a switch at the front for the remote as i couldnt be bothered to try and discover what wire would act as a remote and plus sometimes i like to have the music a little suttle so i can just switch it of with the flick of a button
. i no you can also run the line out convertor from the rear speakers but the rear door cards a ass to get off.