There are 3 ways to fix a auto headliner ...

1. The right way by cleaning the headliner well and replacing the material with a high quality headliner material and adhesive.

2. You can rip it out and just not have a headliner in your car or truck - bare metal or either the bare headliner board.

3.Or use a patch method like putting thumb tacks?(if they will hold) in your headliner to hold it up. A patched auto headliner is one where you just put a bandaid over a sore that needs stitches.