Didn't make it home in time last night, because I started a new conquest against all the rattles in my cab. The poly mounts I installed throughout the drivetrain show no mercy in the noise department.
I pulled apart my driver's side door, since it was closest to me and I could hear it the most, and found that I had only put in my new speaker with 3 bolts. A 4th one and fresh loctite on them all cured it right up.

I proceeded to pound and wiggle more peices of the door looking for rattles and found this bad boy. The bottom rivet had corroded out and was letting it flop around when the window was off of it.

I drilled out all the rivets, blasted it, and gave it a nice coat of Cummins Beige before putting it back in place with more loctited machine screws.

I siliconed my kick panel vent closed since all it did was rattle, leak water, and let in cold air even when closed. I even took some Velcro tape and went around all the interior panels I was too lazy to put all the screws back into.
Now I am able to hear the next level of rattles. My main offenders at this point are the covers for the seatbelt spools and the A-pillar plastic is squeaking on the dashboard. Then every other piece of plastic or metal in there.