Nah. The back up camera works just fine, even with its crap resolution.
Rear window is completely useless. I never use it. I can easily do without a rear window overall.
I remember drivers ed class, it was exciting when we jumped on the back of that Dinosaurus for the first time. We were instructed to use the mirror with "some" assistance by looking back over the seat. The windows were small and pretty much crap.
The Drivers ed Dinsaurus had left and right side mirrors installed and we were particularly trained on using those mirrors.
I have backed utility trailors as well as boat trailors and my training kicked in from the stone age of using the side mirrors. I seldom if ever use the rear window to back up as the side mirrors offer all the visability that is needed. I find I can easily back up any van, box truck, RV etc as the side mirrors are giving all the view that you need. But I have to say this, the ability to use those side mirrors comes from practice, practice, practice.
I agree, the back window is limited but I don't understand why you want to look out of that junk anyway when you have the rear view and side mirrors to use. The VOLT was designed with some interesting limited viewing from almost all angles. Even the front prevents you to see what is low and in front of your car. Hopefully, the sensors will see something and warn you before you hit it.
My driving experiences with other vehicles have been a huge help, particularly with backing the vehicle with side mirrors, But then again, that is just me......