Personally, I do not use the exit screen at all really. I just turn the ignition off, and the computer goes into standby. Start the car, and it resumes.
As for the layout of the buttons, there is no winning scenario here. If I move the power button to the left, then some are going to want it on the right. So, basically, it is what it is.
One thing I do not understand, is the need to have a button (based on a 7" screen in the car) 4 inches closer. I would imagine users like this use only the station presets 1-3 on their head unit, as 4, 5 & 6 are just to far to reach