What I screwed I first dipped the screws in gorilla glue and gave them a spritz of water.
I couldn't keep a screw in it other wise.
I haven't had near enough trouble to actually replace a panel or trim yet but if I do, a little experimenting with some stain, and it's getting either real wood or pvc trim.
For now I have aslo just screwed or glued the pieces back on.
I have read, and until typing this had forgotten I tried it for the first time three days ago:
Spray foam is an excellent glue. I used it on aluminum skinned foam board. It really stuck the foil together well.
So messy, and like stp oil treatment, if someone somewhere in the county is using it, I'll get it on a good shirt or in my hair.