I have a 98 GT vert with a factory head unit. I am hooking up a 12" sub with an aftermarket amp. I tried to follow the dirctions from http://www.mustangworld.com/ourpics/fcar/despeeds1.htm on how to wire from the Mach data cable, and run it into the high level input in the amp instead of using a line out converter. The only problem is that my data cable has six wires instead of just four. It has two black wires with white stripes and one black with green stripes. The other side has two black with green stripes and one black with white stripes. When the data cable is uplugged, all the speakers work (except the door ones i think) but the they are not running through the amp. The high level input on the amp requires a R+, R- and L+, L-. When I hooked up the the right and left +'s to the black/green stripe the amp powered the sub. Even without the negative ones connected. Actually it powered it hooked just to one black/green. So is it not the data cable that I found? I went ahead and hooked up the R+ R- L+ L-, but I don't know if they are hooked up to the Real right and left side. Everything seems to be working right, the sub powers up and best of all no smoke comes out anywhere. Any one have any other ideas on hooking it up that way?