Finally did mine the other day. Learn from my mistakes.
-After laying the headliner out, trim the excess off the ends so it's easier to work with especially if you're doing it alone. I didn't so I had over a foot hanging off each end. One side/half did OK but the other got slack and bunched on me when I was laying it down and stuck immediately, and then the opposite side from where I was holding touched down. Plus having a coat of glue on the headliner itself means if it happens to touch itself it sucks. F dash dash dash multiple times. Couldn't pull it back off and when I tried it would just catch somewhere else. It was like trying get a really bad booger off your finger without having anything to wipe it on times 1000. My wife was going to be off work the next day and told me to wait but nooooo old Steiner has to try everything alone. Of course she made fun of me later, but now she can't see it.....at least until the swelling goes down.
-If you can find sawhorses and a piece of plywood or at least a few boards for support that's the way to go instead of laying it on the ground like I did. On the ends you need to support the back of the board while pressing so it doesn't bend and crack. I didn't have any problems with that but i think it would've been easier to work on if elevated.
-Two cans of the the Permatex Body Shop high heat headliner adhesive was enough to do two coats on the board and one coat on the headliner. If you follow the directions (five minutes between coats and five minutes before final assembly) it will stick IMMEDIATELY.....so hard that on the places I tried to pull up it started pulling the board off or tearing the foam off and this was before pressing it down. On some of the youtube vids it looked like people sprayed the glue and then laid out the headliner right away and could reposition it a little as needed. I guarantee you ain't doing that with this stuff if you apply it using the instructions. Hopefully this also means it ain't coming loose.
Overall yeah I've got a few wrinkles/bunches in it but a couple will be covered by the full overhead console, and at least it'll be better than feeling like I'm riding under a deflated hot air balloon along with foam snow going everywhere when the windows are down. Maybe I should've just f'ed up the whole thing like that so it would look like wrinkle finish paint or like a giant brain. I'm trying to work up the motivation to redo it but I don't think it's going to happen any time soon. Don't let it scare you though, it would go pretty good I think if you don't follow my lead.
1998 XJ Classic driver
1998 XJ Sport spare parts supply