I have a few ground effect trim pieces that are not fully flush with car door. These are the pieces at bottom door. On either end they bow out from door a bit. What is best way to get them flush? I tried double sided gorilla tape and that worked initially. But after driving around one day, they loosened a bit. I have some 3m body adhesive tape I can try. I think part of problem using tape is that trim piece interior does not have a surface that is parallel with door. So in using tape, there is not much contact area. I may try more tape, making it longer across trim piece to get more contact area. Annoying since if I pry trim back a bit, it wants to sag away from door more.

 

Have u tried heating it up with your wife's/girlfriends blow dryer? It might have twisted/warped over 30 years.

 

Use a heat gun on the outside of the trim because u want to bend it inward. U may have to remove the trim completely to flatten it.