Here is a link to where I posted about my h/u install. http://www.gmforum.com/t282444/
I also ran a switch from the cigarette 12v source to the red accessory wire to the h/u. I have a choice now of turning the cd player off or flipping the switch off.
Are you meaning your accessory wire or the remote wire for the amp?
I grounded my amp in the same location the battery is grounded. Although I have the amp sitting in the front passenger corner of the trunk. So that the ground wire wasn't more than 3 ft..