Making Trunk Panels

I just finished up the framing in the trunk of my car and I'm getting ready to stretch the fleece for fiberglass. My question is this. How do you recomend keeping the frame in place without moving while strechting the fleece tight??? I thought of stapling the fabric to the bottom of the frame and then somehow fixing the frame in place to the floor of the car by means of screws. Only problem with this is I can't really get behind the piece to unscrew it after laying down the resin. So, what methods have people used? What are my options? Thanks in advance.

I suppose that would work. I was just hoping to avoid any extra finishing work on the faces of the panels.