I installed an aftermarket head unit (A4 B6) yesterday and I've noticed the rear speakers and sub are way under powered. I believe the rear amp isn't getting switched power from the ignition to power up. We had to run a wire from the head unit harness to the fuse box to get the head unit to come on so I believe we should have spliced the amp switched power into the same source when the head unit was out. However, the unit is now in and it seems near impossible to get it out without destroying it or disassembling half of the car. Now, what I'm thinking the easiest route would be to splice the switched power input to the amp (in the trunk) with a switched power source somewhere back there, maybe the cig lighter that is back there (not sure if it is always on or powered by ignition)... does anyone know if there is a ignition based power source back there? Is this a bad idea in general? I'd be grateful for any thoughts or suggestions on the issue or even corrections if I'm wrong in my assumptions. I don't think it matters but this is a non-bose system. Thanks!