That's a tough situation. Does your rear shade go all the way up or does it leave a small gap near the top like in the gif you posted?
Also, are you absolutely settled on a rear dashcam? 90% of accident situations will be captured by the front, and even when someone rear ends you, a front dash cam can show that you didn't make any dangerous/illegal maneuvers. If you can show that, it means you are not at fault.
If you're okay with a single channel and it's in your price range, go with the single channel DR750s. Alternatively, for much cheaper and essentially the same quality, check out the Vantrue T2. I have read really good things about that camera.
One other thing that I will add that if you get a camera that doesn't include an SD card is to make sure to get a dashcam optimized SD card, such as the Sandisk High Endurance. Dashcam place a lot of read/write cycles, so a regular SD card will fail more quickly. Fortunately, they are usually on sale and pretty cheap!