Is there a way to disable the defroster Vents at the foot of the front windshield when the front facing vents on the dash is on AC/Heater? I have dry eyes and with the front facing vents, I can control where the air blows, however whenevwr the air is on regardless AC or heater, it automatically has air coming out of the windshield defroster Vents too. There needs to be an option to turn on only the front dash vents and not automatically include the defroster Vents.