Re: Rear windows and wind buffeting...
It's an aerodynamic thing. As it was explained to me, the air entering the vehicle through the open windows has to displace the air already in the vehicle through the same open windows, so there's an in-out thing going on.
The same thing can happen when the sunroof is open, which is why there's the pop-up panel at the front of the sunroof. The pop-up panel changes the airflow (creates a vortex or something like that) to allow air in and out of the open sunroof at the same time, preventing buffeting.
If you want to experiment with it, just reach up and pull that pop-up panel all the way down when your sunroof is open at speed. Same effect.
Of course, be careful when and where you try that since you're taking a hand off the wheel.
As someone noted above, this isn't Jeep-specific. It's happened on every four-door vehicle I've owned.
2011 Jeep Grand Cherokee Overland
3.6L V6 4x4
Natural Green Pearlcoat/Dark Frost Beige-Light Frost Beige
ACC/Chrome Fog Lamp Bezels/Slush Mats/Cargo Mat/Door Sill Guards/Splash Guards/CravenSpeed Stubby Antenna
Ordered 4/15/11; Built 5/2/11; Delivered 6/4/11