How are they going to know? Maybe a prism on a stick to see where your shifter is selected....

 

Most cars can shift between nutral and drive without touching the button, it's been this way for 20 years.

 

I remember seeing something in the "tech" section of Road & Track a while back on this subject. They asked some manufacturers to answer a reader's question about shifting into neutral to save gas while coasting. If I recall correctly, they indicated that it wasn't a good idea, either moving or stopped. In a manual transmission car, the point was made that you may get into an emergency where you'd need the power/control and not have it while fumbling to get back in gear. In an automatic it was noted that the wear you'd put on the transmission/shift linkage would be much more costly than the gas you would save, if you'd get any gas mileage advantage at all. I am guessing that the internal parts have to rev-match when you get through coasting and drop back in gear. I also recall discussion of how certain cars actually rev higher in neutral than in gear with your foot off, so any gas mileage improvement may be an illusion. I am no expert at this, but someone may want to ask GM their take on it. God Bless, Marc