Hi all, thought i'd ask this in here too as the ice section isn't as busy... I'm wanting to install an aftermarket sub and amp in my a4 avant. I have the normal concert system (non bose). i'm aware that i'll need a 4ch amp to run the back speakers and need to run a new power cable and what not, but from reading some of AndyMac's posts i need to use the pre-outs, remote and screen cable. I know i need to get a RCA cable a clip the ends off it and connect the cores of the cables to the pre-outs, but what do i do with the screen wire??? Do I connect the 2 shield wires from the L and R RCA's to the screen wire? this is the only part i cant find any info on after a good search... :/ thanks Stu.