got a 08 armada SE...i have a plug n play tow harness that i was told i can plug into the pre wire on my armada. Now im being told the 08 SE has no factory prewiring and that Nissan has to wire the truck if i want it. I having a hard time comprehending this...the dealership showed my i need a part called trailer wire harness...dont i already have that ?...to avoid the high cost my local aftermarket shop told my they can hard wire the harness to work. All i need is the 4 pin connector...i dont need brake function.