2005 4.4i: wind noise in dash?

[DesertRat]

So I just drove home (Denver) my 2005 4.4i (w/ 34k miles) from Ft. Wayne IN. AWESOME CAR! I purchased it from a dealer and when I test drove it, when I got up to about 80 mph there was a weird noise coming from the dash/window area just behind the instrument cluster. When I asked "what's that noise" the genious sales guy said it was the noise coming from the wiper. I wasn't going for it so I hit the wiper to see and sure enough, noise went away. Now fast forward to the last 300 miles of my 1100 mile drive back and the noise started again only this time it was LOUD! I was pissed. After some troubleshooting real time, I've concluded it has to do with the effective wind speed. When I slow down to 70, no noise. But at 70 with a 20 mph head wind I get noise.

So I'm wondering if there is an air duct or something like that that might have something stuck in it that I can quickly check.

Thanks.

-DR