“Does anybody actually do that?”
In the modern age of air conditioned cars with radios, CD players and closed windows it’s kind of hard to tell. :)
Many but not all used to do so—on two lane roads of course, not freeways or multi-lane city streets.
I think some still do when they are passing bicycles on narrow roads. Some of those aren’t being courteous though.
I spent 10 years in a car with a non-functioning AC, plus I’m an on again off again smoker, windows are open all the time. Never heard it once. Don’t think it happens.