Got a mounting bracket in place. Made out of 1/8" x 1/2" x 3' aluminum stock. It survived the first test drive.
Since the material is so fragile, I don't expect it to last too long. When it starts to discolor, I'll see if it can take a coat of paint. This grade of foamboard is only paper covered, after all. It's $11.00 / sheet retail. The better quality stuff, "Gatorboard," is plastic covered, and about $60.00 / sheet. (That's when mistakes get costly).
I might go back in and try to correct the cutting mistakes, which are too obvious in that white color. Only other thing is you lose 2" of headroom to the rear glass. At 5' 8", there's room to spare for me, but if you're tall, you'd have to slouch over
