I'm assuming you are using relays at the rear main power/ground to control it? Otherwise you would still be flowing the full current through the switch and it would be pointless to run a main power and ground to the rear.
Right, like a relay box in the back with room for 4-6 relays or something like that, just so that if you are going to go through the trouble of routing cables, you only do it once, and then if you decide to add something else to the back of the truck, you just throw in another relay and wire up your accessory.