These rear window inserts are made from thin sheet metal pop-rivieted onto a cardboard backing.  I used numerous old VCR circuit boards and wires. For the other side I added 2 Pepsi cans painted blue to look like capacitors!!!

The "Mr Fusion" unit, as you can see, is pretty good.  The lower black part is a plastic salad bowl painted black with stick on 1/2" foam weatherstripping to simulate cooling vanes. The upper white base is a microwave splash shield used to cover bacon and other items that spatter.  The Fusion unit itself is a Rubbermaid juice container with the handle cut off.  The red latch is a simply a piece of wood I crafted to fit and painted.  The decal are made on my computer.  The logo isn't accurate but close enough.

The rear jets are 1/4" Luann plywood. The center vane has cut slots for the louvers. Getting the right angle and shape on the jets was the hardest part.  I'm pretty close but would probably make them a hair shorter and angle back a bit more if I did it again.

To attach all the pieces onto the main rear deck board I used pop-rivets and small bent pieces of metal that I drilled a pilot hole in.  The pop-rivets allowed me to not have anything hanging below the board (like nuts and bolts) to scratch the cars engine cover.  This was the primary concern.

The entire rear deck add-on unit is one piece making removal and installation a matter of minutes.  The only real time consuming task is removing the rear sunshade