I took inner panels off the doors and insulated all 4 plus tailgate, then used trash bags to replace old craft paper GM used for insulation, put on new door panels and weather stripping. I took roof rack off and freed all the adjustment screws up so the lateral slats will tighten up and put anti seize on the screws
I've cut up an old shower curtain before. What works well for adhesive is the black 3m double sided foam tape.