ABS Headliner

I got my abs headliner from Rock Auto. It is covered with fabric not vinyl and the adhesive looks like it's going to keep it on there even when it gets hot.
My front windshield gasket is new and the rear glass has the original gasket. It is not as flexible as the new one.
I'm not inclined to peal back the fabric to trim the plastic. I think I'll do what I can to soften the back gasket and make sure the headliner can slide in on top of it as much as possible. If it still won't go in in the front I'll find a trim channel and let it cover the front gasket. You have the rear view mirror and the sun visors providing decent anchoring up front anyway...