Lexan Rear
 

I drove the summer with the glass swapped out. Here is a video of the panel removed. Getting new glass back in. I need the defrost for winter.
Was riveted on with some Urethane to waterproof it. it only used 1/4 inch. and had no problems with noise or wobbling of the plastic. This was due to the concave opening which gave it rigidity as well as the brake light for centre support.

http://youtu.be/ErUeBu95jcY