Here is what I thought about doing at one point. Have a small piece of sunbrella made to cover the sliding hatch area and snap up under the windsheild. Snaps wouldn't work so well on the front so (forgive me I don't know what it is called) have piping on the canvas that slides into those round aluminum channels like you see on some enclosures. Could also use the channel/piping on the sides if you wanted to.
I would probably only use when trailering/trolling in the rain cause it would make it a pain to use the slider!
BTW - got some pics yesterday. Gotta get my thumb drive out of the truck. Pics up before lunch time...r
Canvas covering area in red.