For such a "safe" car, I think Tesla is under-performing in their presentation of data department. Hopefully v9 will help here, but wouldn't it be easy enough for them to have a pop-up next to the image of your car with the rear-camera super-imposed any time you signal? Below is an example of a pop-up if you signaled left. (Ignore the full-screen rear camera image, most people don't drive this way...I left it in for context so you can see where my pop-up image came from)
Or even just the whole image:
Or even just the whole image: