I've noticed this today, not sure if I've noticed this before because it's getting colder now and I crank the heat up a little. When I'm satisfied with the heat and turn off the blower motor to 0, I can still feel heat in the vent, sort like its between level 0-1 on the blower control. The problem is that, it won't shut off even after driving for a while. If I divert the vents it will still vent it out somehow.
Based off of this image below, shouldn't the vents block a significant portion of the heat/AC while the blower motor is off?