Is there any way to turn the screen off once driving?

 

I know if you don't touch the "OK" button when it first boots up it will go black after a minute or two. Not sure if you can turn it off after that.

 

Of course you can, hit setup, you will see Turn LCD OFF button. To turn it back on press any button.

 

This is what I do when I drive in areas with no Navi coverage. You have to hit "OK" if you want to be able to use voice control for the radio and climate control, so I'll hit "OK," then "Setup," then "Display Off" (I generally use the voice command for this rather than fiddling with the buttons).

Note that if you're in an area with no Navi coverage and you display the "Audio" screen, that screen will remain frozen when you turn off the radio and you'll have to repeat the process noted above to clear the screen.