I ran my wires along the passenger side. Pretty easy. The hardest part was grabbing the wires once you pushed the harness through the taillight opening. I popped my roof liner down a bit and was able to grab it after a few tries. Then it was pretty simple. Be careful when you remove the pillar cover on the rear/passenger side. It's got a weird clip that tends to bend when you finagle it. I ended up bending mine where it would not clip back in properly. So just go easy and pop them out if you can.
Then you can route the wires down (away from the airbag of course) and under up to your upfitter. I have my outter ambers tied to the same upfitter. Using the factory cargo connection for the center s2 cargo light.
It's not that bad. The hardest part I tell people is just getting the gasket lined up perfectly. It's double stick and once you put it down you CAN move it a little (peel it back up). That and the screws. It's a little tricky to get the screws to line up into the included fasteners. I found using some painters tape to HOLD the fastner onto the truck AND bending the fastener out a bit with a screw driver helped. If you don't bend the fastener out you'll scratch your truck (not that anybody would EVER see it, but ya know... i had a truck that was a month old when I did mine).
