[benj111]

You can just use the screen for infotainment and satnav though.

I already have a screen showing what radio station is playing, and one on the dash telling me where to go. If a screen is required for a backup camera, just combine it. If I'm reversing I probably don't need the satnav anyway, whereas if I'm reversing or using satnav I probably do need other functions which just means you need an even bigger screen so you can fit everything on.

[emiliobumachar]

You're absolutely right, but my point is that the minimum number of screens is no longer zero.

[bluGill]

Sure, but the screen need not have any touch capabilities. It doesn't need to be large either. A 2 inch screen is large enough for the camera functions.