The plastic clips do not have more holding power, especially over time. They get brittle when they get older. I use the Au-Ve-Co 12134 clip for door panels, but you're going to have to use something a lot stronger to hold the headliner in with that much weight. This is an offset clip, so the holes in the panels have to be offset 5/8" from the holes in the door. FWIW, the aluminum may have been free, but it's going to rattle, especially the headliner. You may want to re-think this project.
No one lives forever, the trick is creating something that will.
Last edited by DanTwoLakes; 06-05-2013 at 08:53 AM.