Well....good news and bad news. The good news is that I had a plan all laid out to get some serious footage from many different parts of the vehicle, put it all together in one video and see what you guys thought. The bad news is that as I started my second set of tests, my GoPro suction mount came......unsucked. Obliterated the suction cup and waterproof housing and dinged up my Hero 4 but it was laying face down in the road with no lens damage whatsoever. So....I'll re-up my equipment and give it another shot. Here is the first test. Honestly, there is nothing really to see here (which may be a good thing).
https://www.youtube.com/watch?v=kYdMwlcbIaA
20 secs each at 40mph and 70mph (constant speed) of the rear window meeting the lift gate.