I am attempting to build a hard top (hardtop?) headliner out of a sheet of Reflectix, and lining it with vinyl, or headliner fabric.

I'll start off by making a template out poster board on the inner roof of the car, following the grooves already in the roof.

I'll transfer over the template and cut out the Reflectix to fit. I will have to check the clearances, and probably trim the Reflectix where the roll bar is very close to the top.

Those are the easy parts. These will be the more difficult parts:

Attachment: I will need a High temperature glue, which can hold the (light) weight of the liner, plus its covering. The key is obviously high
temperature. I do not see a way too make this an easily removable piece. Unless there is a high-temp double-sided
tape.
Can/should I use the removable trim plugs in the HT as additional attachment points?

Covering: Should I use something between the Reflectix, and the covering material? I was thinking of something like a thin piece of plexi, to
make the material lie smoothly, and not look winkled. If I use vinyl, with a thin layer of batting, it might be forgiving enough
to hide the wrinkles in the Reflectix. I'm wondering if adding anything other than the cover will b a recipe for disaster.

Any ideas or help that you guys can provide would be awesome.