I take it you either have never driven a vehicle with a backup camera or have driven one, but not in inclement weather. Rain or snowy days make the backup camera totally worthless.
Now to the physics part. Since you claim to be a physics expert. Could you please tell us the drag coefficient on the average auto side mirror, and how much drag will be reduced by replacing with cameras and the over-all gas savings. Use your own cars as an example. Since you’re an expert on physics this calculation should be trivial.