How's this idea? Pull the sunroof outa some Ford fox body in the boneyard. Any sunroof would do, but I like those. Use the factory hardware to mount your new panel as a removable sunroof. Make the top of your body opening like a trunk surround and use a trunk rubber to seal it inside. Trim the acryl. with a u-channel of steel, think 80's camaro back window, or stainless to be pretty while adding edge strength and providing a clean mount for the front steel pieces, the ones that provide the hinging motion, that slip into the body. Use some narrow JCWitney self adhesive rubber stripping around the bodies outer edge of the inside of the panelled area to help deter water entrance. Because of the cars rake I'd weld the bung's for the rubber weep hoses into the front of the opn'g and run those down the a-pillars to the underneath. And the pay-off? Open air! Open the windshield and the top. Hell, take the top out if ya want! I'd suggest that having a panel that large on top raked at an extra 10degrees or so when open would add downforce and help handling too. I'll post my other idea on this one after this first one has time to sink in...