in my previous oldschool vehicle, i had a triangle warning in the mirror and a beep...
Here i didn't figure out how the warning works actually... so i presume its very soft or they think you look at the screen and see the detected vehicles...
Icon in front of the driver is not good. When you intend to make a lane change, your eyes are not down in front of you. You are looking toward the side. Just follow the Honda lead.
We already have an icon to display the view from the rear camera. Implementing icons to display the view from any of the side cameras should be an easy patch. When backing out of a tight parking slot in a parking lot, the rear camera isn't useful to see adjacent cars or obstacles on the side. I've gotten multiple scrapes and dents in cramped indoor lots.
And even better, provide the option that will show the left or right hand camera, when the driver indicates to change a lane on a freeway e.g. over a certain speed i.e show the blind spot (if that would show on the camera).
I suspect sonic sensors are much better/safer than visually looking at a camera image. Next is the User Interface to the car and how to keep human from overriding too easily.