Actually, forget gluing the the headliner, you need a manufacturer to do that, in order to have it stay. The heating machines etc. are over a million dollars. The only real option is to sew everything together, you might get "bunching" here and there, but it's totally not worth researching the glueing aspect, wookie already spent a fortune trying that out. Oh, and check out my website, http://www.zamiam.com , it will tell you the process by which we figured everything out.
Dang has it really been 2 years? wow..holy pajeebies... no way!