Thanks for all the insight guys, this sound has been making me crazy. I'll update if the sound returns on a colder morning.
So far, I've only taken it for a test drive in 60 degree temps, but the sound that has annoyed me for months is gone. Double-Sided Foam Mounting Tape (12-Pack) (5) Questions & Answers Hover Image to Zoom. Hopefully the pictures below better illustrate what I'm babbling about. Once you have cut slits for each rib, now stick the tape firmly to the trim piece and reinstall it in the truck. At each rib, cut a slit in the foam tape to allow the tape to sit completely against the main part of the trim piece. Then, using a brand new piece of foam weatherstrip tape (I used 3/4" x 7/16" rubber foam weatherstrip tape from Home Depot $4.18), lay the strip along the entire length of the trim piece but DO NOT stick it down yet. Once you have removed the A-Pillar trim, completely remove the foam tape installed by Toyota. Here is the solution I used to fix it which I think is very simple. This allows a portion of the tape to not adhere to the trim and is likely the cause of the noise.
Specifically because the Toyota-installed tape is simply placed up and over the little plastic ribs on the trim piece. Depot or Lowe's and buy the appropriated number of rubber cup chair leg. After reading through this entire thread, I agree that the problem seems to be with the foam tape installed on the inner side of the passenger A-Pillar. vibration throughout the framework of the house. Its strong bond holds up to 15 lbs. That rattle has been driving me nuts for about two months now. Virtually clear, this double-sided permanent tape is perfect for mounting glass, tiles and artwork.