Threads merged.

Bernoulli's principle. High velocity air over the car. Low velocity air in the car. High velocity = low surface pressure, low velocity = high surface pressure. Gases always go from high pressure regions to low pressure regions to achieve equilibrium.

So, there is a high pressure area inside the door great enough to make the gas molecules go through the switches, into the cabin, and finally out the sun roof. Pretty stagnant air in the door I'd say.