As promised a pic of the Kammback.
It is 16" long at the apex of the roof. It looks like it would block most of my rear view, but I can only see about 1" of it from inside the car. It is made of 1/8" ABS plastic I got off Ebay for $28 for a 4' x 8' sheet. I used some 3/8" stainless steel pipe to support it and secured it with 1/4" pan head screws to the original mini Kamm mount that came on the car. No A-B-A testing done yet because the new snow tires have messed up my MPGuino calibration. My ODO is under reporting by about 12% right now.
Eagle eyed viewers will also note my new charging port installed in the rear bumper. It connects to my battery charger in the rear for the new deep cycle battery for my alternator delete mod. It is a NOCO Genius model I got from Amazon. The plug port is really nice and has a rubber cap to protect the plug when not in use.
https://amzn.to/2DpKVE8