where did you source the Kaon pannel?It's a very well built product. I don't plan on storing anything heavy up there. Right now I have a roll of shop towels, a spare rain jacket, windshield sun visor, and a set of reflectix panels I cut out for when I camp and sleep inside the GX. I'll probably store a sleeping bag up there as well and hang a fishing rod or two underneath it.
I chose the Kaon shelf because I didn't want something that reduces rear visibility so I decided against the window panels.