I have a '99 Corolla that’s served me pretty well but lately the cloth on the headliner has started to separate from foam padding on the ceiling. It started around the top of the rear window and I tried to fix unsuccessfully with some artist’s glue but it didn’t take.
I decided to let it go since it really wasn’t obscuring the view but this week it’s started to separated in the front. It’s just a small section, less than 6 inches wide but I want to stay ahead of this before it gets too bad.
Replacement material can be puchased through places that sell crash repair stuff, and the adhesive (spray on) can be purchased right at the local parts store.
Or, you can try doing a repair on this small area with a two part epoxy from WalMart. However if the rest of the material is on its way down this may be only temporary.
There are fasteners available that will hold up the headliner. Available at most auto parts store in the help section isle https://www.dormanproducts.com/cgi-bin/vm91corp30r/item-dtl.w?sid=0x00f8cf20&item=45690&icrid=&clt=hwrap1&vsrch_str=headliner&vsrch_brand=ALL&vsrch_cat=ALL&st_amount=&end_amount=&start=&vfrom=&prev=&vnext=&category_list=:0
Personally I used thumbtacks in my 97 Nissan truck when it started doing that. There is a MDF type material that serves as the mold that the foam and headliner cloth are glued to. It takes thumbtacks pretty well and they hold. You could get fancy and set them in a pattern to look like button tuck upholstery. A card of tacks cost something like 37c at Wallyworld.
Any fabric store will sell you upholstery screws, which will hold up your headliner for pennies.
“bow” it up with thin wood slats, if you want to take the cheap way out.
I’ve had very good luck with these fasteners. If one spaces them evenly, it almost looks as though the factory installed them.