Tim,
I noticed in one of your pictures you are using a vibration dampener and covering the entire back of the cab. Then the later shots seem to show you have painted that portion around the rear window. Did you later decide not to cover that area?
The first photos were before I re-installed the rear panel. The sound and dampener and insulation is actually under the beige colored panel. There are only a couple areas in the cab that i did not put the insulation, etc.. Those are the back side of the firewall that you can see when you look in. Everything else was covered by the rear panel, headliner, bottom corner panels and kick panels.
I highly recommend doing this as it makes a HUGE difference in the amount of road noise and rattles. I glued everything down with the exception of the floor insulation (just incase I get water in the cab I did not want it to sit in that insulation and cause rust problems down the road).