I noticed the other day that the pillar trim on both sides is pretty loose and was wondering if anyone knew how I could get it back to normal since its going to drive me nuts until I stop it from moving all over the place.

 

Bump. Don't wanna have to start ripping stuff apart without knowing what I'm doing first...

 

there are christmas tree clips that slide on the trim piece. yours are either loose broken or both. you can buy replacements either from autozone or classic industries. i replaced mine when i replace my headliner, its worth it because rattles make me crazy.

 

just replaced my headliner and the trim tree clips as well. Just a side note, the ones i got from autozone for gms were to big for the trims retainer piece, i just chopped a tiny bit off one side of each and they fit like a charm.
I used the white GM Panel Clips from autozone.

Best of luck.

(DONT USE THE HEADLINER REPLACEMENT CLIPS THEY DO NOT FIT)