I got my blind spot camera working today (I think) and everything cabled in. I found that if you take the storage compartment over the cupholders out there are some pretty good crevasses for stuffing things - so I jammed a lot of wiring up in there, along with the 12V to 5 V converters that most devices seem to have built into their cigarette lighter plugs these days.
If you ever get a chance to check out my rig, one of the mods that has worked out very well for me in the cab is the piece of aluminum square tube about 3 inches above the dash. It makes a great place to mount devices without drilling holes in the dash or resorting to double sided tape. I have mounts for my GPS, inReach, iPad, TPMS, and forward camera all bound to it.