funny you mention this now...but i noticed this the day i picked mine up. I agree, I had only 1 window down maybe halfway in the back and the car had this loud interior violent pulsing sound....was hard to heard anything, including radio. Same deal when i did the other rear window......I was to chicken to post first about it LOL
actualy with my Rav one time 3 weeks ago with the sunroof open I did encounter wind buffetting but i could not duplicate it again since.. Maybe it was just a weird wind direction and temp and other conditions??
This problem is quite common, and it happens in almost all cars around, and sure happened in the previous RAV4s. When the back windows (both or just one, it does not matter) are down and the front ones are not it creates a resonance phenomena inside the cabin, I think because turbulence ocurrs, but not sure. It is quite unbearable but it is the way it is. I don't think it will generate any recall notice, and certainly it will not be fixed.
It is not as bad when the front windows are down, maybe because it changes the air flow pattern, but still a low frequency rumble could be felt.
So, keep your kid in the back from lowering the windows in the highway. That solved the problem in my case.
I'm assuming it's not winter where you're at, otherwise I doubt that you'd be driving with the windows down at 65 mph (at least not too often).
Anyway here are some unsolicited suggestions:
1. Don't leave the windows open. I remember seeing something on TV that proved that driving a car with the windows open w/AC off SIGNIFICANTLY increased fuel consumption. While driving the with the AC on w/ windows closed did NOT significantly affect MPG (control was driving with the windows up and AC off).
2. Maybe Vent Visors will work (theoretically), but I've never tried them, but maybe someone else has.
Remember everyone I live in sunny Calif. and when it is 75 deg. outside and
you are driving 45 mph who wants to use the air conditioner. I have
owned 15 cars in my lifetime and never had this problem. The
problem is the headliner has an air gap between it and the roof and this allows it
to pulsate. I am in the process of talking to an upholsterer to have him put in a thin piece of foam to take up the air gap.
Nearly all modern (built in the last 10 years) cars that I have driven have this problem. It has nothing to do with air in the headliner. Just pressure waves moving through the cabin when a window is opened. Any open window will kill the aerodynamics by the way. Most older cars just had such bad aerodynamics to start with that the problem never had a chance to show up. The problem is well documented and has been discussed at length in many places, including at least 2-3 articles in different car magazines over the years that I recall reading. Best way that I have found to limit the buffeting is to crack the front windows a bit. Play around with opening them different amounts to get them to a point that it does not bother you. You can always do what I do here in warm, sunny Arizona and keep them all down and the sunroof open and the radio cranked up. Sorry that the link in my first post seems to be down, contained a good scientific explanation of the problem and how engineers are just starting to be able to look at it. I did find another link talking about the A/C vs Windows down question on fuel economy though.