Update. Leak has been fixed! I ended up pulling the whole quarter panel off to seal the whole front corner of the cab. There were many leaks but the one that was hardest to track down turned out to be coming from the top passenger corner of the windshield and running all the way down the a pillar (out of sight, until I pulled the trim off and sat in the truck during a rain storm) until it pooled in the bottom. It seemed to be where the windshield trim makes the transition from being curled over the glass, to being extended out on the side, roughly an inch or two in on the top edge from the corner of the windshield (kind of hard to explain but hopefully that makes sense). I just forced some seam sealer in where the hole was and also re-sealed the metal joint on the a pillar. Hopefully this helps someone else out there.