I mounted mine behind my back seat. The aux switch wiring is tucked under/next to the battery tray (you have to pull the battery to get to it). There are 2 sets of wires, one with red tape on them, those are hot. The other set are for jumping into the cab. Basically pick the wire you want to use with the red tape and connect it to the same color wire, that will pull the power through to the kick panel in the front passenger seat. From there I just pulled the power wire along the base of the doors to the back seat. You can ground it to any of the grounded bolts that you will find along the back panel of the truck. There are a few rubber grommets that plug the back of the truck that can be used to route out the exterior antenna cable, I just cut a little "+" in the grommet with a razor blade and fed the cable through. It is a little tricky to get to the cable between the cab and bed, especially because there is a little carpet type material that you have to push away from the cab to slide the cable out from under. For the inside antenna I just ran it along the base of the driver side rear door and then under the carpet under the driver seat and up to the left side of my center console. That wire was barely long enough so you may have to get creative with that one.
I probably did a horrible job explaining that but I hope at least some of it makes sense. I did make a video on the weboost but it was more of a rough overview than an install video, I do show where I mounted it near the end of the video though:
