Menards Headliner and sunroof are in...

I used this:
http://www.menards.com/main/paint/paneling-planking/paneling/fiberglass/fiberglass-reinforced-plastic-textured-wall-paneling-white/p-1503821-c-8170.htm
(The board is pretty flexible. Heating with a heat gun does not produce the best results because it warps the panel)
and Joanns black fabric headliner material to produce this:

In this pic, you can see the little line to the left of the sunroof- I put a "V" in the board so that it flexed into place.