Yes, the car is acting like a giant whistle, but instead of the shrill with a small whistle, it's a thumping, pulsing sensation. Best bet is to crack a window across from the one that's wide open, as you mention by lowering the front windows. This prevents the resonance of the cabin.

Any car can do it: it's a factor of speed, opening size, wind direction, ect. In fact, the little lip thing that raises when you open sunroofs is there to prevent the same effect.

Not just Super White...Super Duper White...