Figured I'd post a response to this as I finally installed my trailer wiring harness this past weekend. The install is easy and the instructions are clear. It really comes down to how much your time is worth.
Assuming like most people you will have never done this before and will only do it once, its going to take you some time. Just carefully taking out the light, removing your jack, dropping the spare tire, tucking the new wiring safely away, etc.
So, anyone that wants to do it, don't hesitate, its an easy install. If you'd rather spend the few hours doing something else, pay the shop to do it.
For those that HAVE done this, as noted on the instructions I was able to tack up 2 of the three "wiring points" (I'll call them) on the exterior cable that goes from the plug to your tail light. That wire has 3 different attachement points. A hard plastic body connector (no problem), a rubber frame connector (almost no problem) and a long plastic connector with a mystery white plastic bar (?) underneath it. No idea how to connect that last point and since its up and out of view I don't see how you could do this. Still, the wire is secured in 2 of 3 places and goes snugly up to the tail light.
I was amazed with how carefully all the wiring is thought out in this vehicle. Every one of the plugs is secured to the body or some type of harness. Its all been designed very well.
Don't have a trailer handy, so, I don't know if the kit works, but everything else in my truck still does. Its a passive connection that didn't go inline with any existing wires so I wouldn't expect any changes.
Hope this helps,
-todd
