I've noticed a strange pulsing in the interior air pressure when my callie reaches 25+ mph. This only ocurrs when one of the rear windows is down and all of the other windows (and sunroof) are closed. It kinda sounds like a blown speaker that has a lot of power behind it that is switching on and off very rapidly (it can give you a headache really fast). Anyone else having a similar problem? I wonder if it has more to do with the aerodynamic properties of the body or if it's just a bad seal in my SXT.