Anyway if choosing to coast in N (davideos is correct that coasting in N is more energy efficient than coasting in D), the driver should be savvy enough to keep the right hand on the selector handle ready to pop it into D or L should slowing or speeding be necessary. No fumbling necessary. I would hope the selector can't be accidentally moved to R when in forward motion!
Umm actually it can moved into R...opps.
Here's the cool part. The reverse video comes up even after you move it back into neutral, and stays on until you put it back in D.
This is definitely NOT recommended as something you do intentionally.