if I had a router, that would certainly be the way to do things.
I'm lucky that I stumbled across the belt sander... I bought it at a thrift store a long time ago and it was buried in a box that I went through getting ready to move in a few weeks. Belt-sander -> chamfered edges!:
Spent some time this evening cleaning things up getting ready to lay fiberglass over the box on the side:
@ aktacoma - The top of the opening at the back is about 6" higher than where the top of the tailgate would be. I think the rear door will be hinged at the top, so the opening'll probably be a couple inches lower than where it is now when the shell's done. That's a good idea, using a couple lift springs/pistons at the back... I'll have to see how that'll fit w/ the whole pop-top thing...
Do you have any ideas on how do do the solar panels proper? They're pretty fragile, so they need to be laid over a rigid base... and if hail hits them they could crack, so maybe pour a layer of resin over them? There are optically clear resins, I think, that might work for that.