EXT Wind noise

Has anyone else noticed the wind noise with the back windows open. I have a 2004 EXT 4x4 with the roof rack. With the back windows down I get a strange pulsating sound caused by the wind that almost makes me sick. I have tried moving the crossmembers on the roof rack around but have noticed little change. Anybody else have the same problem.

For what ever reason, any 4dr vehicle I've driven in the last 20yrs does that. You get that funky air pressure pulsation thing if you roll down JUST the rear windows. It's normal. Just crack a front window to make it stop.

Joel