Cheap sun blockers for the windshield could be modified to fit all the windows for black out panels, otherwise room darkening curtains might be a viable option. Synthetic screen material should work well enough for screens,magnetic tape should work well for attaching it. For the back I would consider making a "wall tent" that will mount to the sides of the rear hatch for late season and inclement weather, could make cooking and waiting out rainy days much more enjoyable, and adding scree panels to it should be a pretty straight forward process.
This is the style of magnet tape I mentioned.
Arrives by Mon, Feb 5 Buy Magnetic Tape Roll with Adhesive Backing - Strip of Peel and Stick Magnets - Super Strong & Sticky by Flexible Magnets (30 mil x 0.5 inch x 50 feet) at Walmart.com
www.walmart.com