Tercel headliner

Duct tape?

If the headliner is coming loose from the edges, tuck it back in and position the trip so that it holds the material.

If it is sagging down in the middle somewhere and you can get above the headliner, use some Household Goop or other adhesive to glue it back up.

There are some great spray adhesives available now that are just the ticket. I have one in my garage called Heads Up Super Duty Interior Adhesive and I have used others although I can't recall the brand. You'll find several at your auto parts store. You spray them on the metal and the material immediately adheres to the tacky surface. Good luck. jor

3M makes a spray adhesive specifically for headliners. You stick the nozzle in, spray a bt and then reattach the liner. Can get is just about any decent parts store or CarQuest. Ooops, that didn't come out quite right...