The remote line is the small line that turns on the amp when the key is turned on. The remote line should be connected to a switch 12v circuit. A lot of people here like to add a circuit to their fuse box (pretty much buy an "add-a-circuit" at Best Buy or where ever and add that to your radio fuse in your fuse box) But you could use your factory amp in the trunk, because it already has a remote line, and tap into that and you wont have to run that line through your car. You'll just need a multimeter to test for the switched 12v at the amp.
