There was a chap in East Yorkshire who used to build raised roofs using a flat roof panel conected to the vehicle with two side panels and three piano hinges to allow them to fold into the vehicle when the roof was down. the end panels have one hinge at the bottom to connect them to the vehicle and push up to support the roof and fix the side panels. the end panels have door seal around them to make the whole lot water tight. He does not bother waterproofing the piano hinges as very little water can get through. He used marine ply and stainless hinges. Very simple, but very effective. I hope you understand what I mean.
The Simpler, the Better!