I apologize and correct myself. Only when the fans are completely shut off that when I hit the Max Defrost will it go to the super high vent settings. If the vents are currently on and I hit the Max Defrost, the vent settings change but not the fan speed.When I hit the Max Defrost, the vents are set super high at the windshield and the rear defroster goes on. I've never tried hitting it again to see of the settings would go back to the previous air flow. Will give it a try today.
This is what the manual says:
2. MAX: (Max Defrost): Distributes outside air through the
windshield defroster vents and demister vents. Can be used to clear the
windshield of fog and thin ice. Press this button again to return to the
previous air flow selection.