Chugging sound when rear windows of vehicle are open

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Here are a couple of previous threads on the topic:

Does this really annoying sound happen in your car, and what causes it, and is there a fix?

When I have either or both back windows open more than a small crack, and at speeds between about 30 and 60 mph, a loud low frequency flutter develops. It is very intense, almost painful, and it’s something in the neighborhood of maybe 150 hertz. It seems not to be audible to passengers in the back seat, since they are invariably the ones who start it by opening their windows, but they show no real awareness of it. I thought it was something peculiar to my Mazda 3, but my sister says the exac…

Modern car design: windows up when driving?

What is it about the design of more modern cars that driving with the windows (particularly rear ones) down creates an unpleasant booming noise? Sure, aircon being standard now means we shouldn’t need the windows down, but sometimes I just quite like an open window as I’m cruising along back country roads. My first car/s sans aircon were fine with the windows down, and also had that little triangular pop-out window in the front seats to ensure a stream of wind in your face on the warmer days. …

Ear pressure in car

Just a guess, but air pressure could be building from air being forced into the car, but not having a ready exit. Both windows open would allow both entry and exit for the air, lowering the effective air pressure.