Cd, stop being a dick. You know why.
Miller, perhaps string two bungee cords from the rear end of the door to the outside edge of the fender, and secure some spandex or canvas over them. The door latch should keep it taut and it wouldn't be too too hard to try.
I've got a project like this brewing in my mind, but a RWD version of much lower hp
It'll be interesting to watch how this one pans out.
Edit: regarding the "huge" stripe. I'm not sure it would work with the window graphics. With all due respect, the Corvette front end and the Civic doors don't really match. Using a bright, light color like yellow or orange could distract from this, and black is always a good "wow" color. Of course if you don't have a really smooth reflection on that rear quarter black would be a bad choice. In a lighter color it may look better, but not white. Just trying to help.