My 07 quad cab has significant buffeting inside with the windows down. It actually sounds like the pounding woofers from the car behind me but is coming from inside the truck, door panels, speakers, or something similar. Although it is loudest with a single window down, it occurs with any combination of windows. Has anyone else had this problem? It is not the exhaust, engine, or body panels but almost resembles a moan but goes on at any significant speed.