Insulation, Peel n seal and other budget insulation ideas

TrailBeast said
I think it got more expensive when bought as automotive insulation.:D
If I had heat problems and no head liner this is what I would use.
Cover the inside of the car with a drop cloth and spray the roof with 3M contact adhesive, then spray my precut piece already done with cloth and pop it in there. The stuff is so light I wouldn't have to worry about it's own weight pulling it down.

I’ve been researching what I want to do for insulation all throughout my Duster and found this older thread. Are you saying that if you had a car without a headliner (like mine), you would just attach clothe to the double bubble insulation with 3m adhesive and then attach the insulation to the ceiling with 3m and just use that as your headliner?