Originally Posted by manisusmc
the rest button is for the winter when the car is warm, it will blow warm air into your car for up to 30 minutes, its just enough to keep everything just about right inside for a quick trip into the store
It's also good for the Summer A/C smell. Airy out the system to get rid of funny smells. It worked for me, I even changed out my cabin air filter. This is the only thing that did the trick... (consistently for a month)