My '87 MM sat for about 7 years and I'm finally getting around to putting it back together. The headliner looks like it's gotten wet at some point in the past and sags badly. I've taken it out and I'm pulling off all the old insulation, but can't figure out how I'm going to get it back in shape and hold it there. So, a couple of questions:

(1) Any ideas on how to get it to hold its shape? The only thing I've been able to think of is to make a fiberglass shell to glue the headliner to. I think that would give the strength to hold it, but would be a real pain in the butt. Anyone had any luck with something easier?

(2) What should I use to replace the insulation, if anything?

Any suggestions will be appreciated.