Someone here posted the idea (I'm sorry, I forget who) to use magnetic sheeting (like they use for signs on the sides of work trucks) as headliner material and attaching the headliner to it. This sounded a lot better than wrestling upside down aerosol glue and a sticky headliner so I bought a piece of 60 mil adhesive magnet from https://www.discountmagnet.com...esive-magnet-5-roll/
I cut it to size:
Then attached the headliner to the adhesive side.
Then set it in place.
Turned out perfect. It also acts like Dynamat in that it dampens the resonance of the roof.
Anyway it was WAY easier than fighting upside down adhesive spray and trying to wrestle a floppy piece of headliner into place.