This feature is ESSENTIAL in Arizona during our humid months. What it does for us is when the car is turned off, and you DONT have this feature (I actually have never seen a car with this feature), the evaporator (the part that gets cold and makes air cold when the AC is on) will condense the moisture out of the air and become wet (when you look at vehicles during the hot and humid months, you will see water dripping from underneath the car for 10 or 15 minutes). What this does is promote an algae/fungus/mold growth on the evaporator. That is why most cars in hot and humid weather have a strange smell when you first turn on the AC. It is the air being drawn through the moldy evaporator. But not our Crossfires!! With the air circulating for 30 minutes after the AC is turned off, hot outside air is drawn through the condensor and dries it off quickly, and prevents that nasty gunk buildup. I am actually surprised that more cars don't have this feature. The only drawback is you need to remember to press the recirc button everytime when you get out of the vehicle.