Just passing on info that might help out a member down the road.
I had an annoying squeak from the center dash area and some rattling behind the glove box area. It only did it when the truck was moving and not at idle. Luckily it's still under the warranty so I took it to the dealer and drove with a tech so he could see and hear what was happening. Anyway, he found 2 loose bolts behind the dash that were attached to the 115v power inverter outlet which was causing it to hit a brace bar behind the dash (the loose bolts were making the squeak and the rattling was it hitting the bar). Glad he found and fixed that. On longer trips it was like a torture...even though the radio was on and people were talking, all I heard was that damn squeak!!
Hopefully this helps someone out somewhere with the same issue or at least lets them rule it out.