My S is sure prone to fogging up and not being able to keep up with the vents. Here's a photo of a recent fog episode. Had been driving for 20 minutes, only floor vents on, exterior temp 28f. All of the sudden it starts pumping humid air and completely fogs up all windows. What would cause this? This is a big of an extreme cause, but it commonly fogs up and requires me to roll down the windows and dump all the humid air.