There is a pocket at the upper outside corner inside of the gen slide and just below the dash. this pocket corresponds w/the bottom end of the windshield side post, and has the opportunity for a bundle of wires to run up the windshield side post. If that is not sealed properly, you will get a lot of wind noise if wind direction is 'optimal.'
Check both windshield side posts, and if there is an opening, stuff the opening w/a dense wad of plastic shopping bags, drive & see if that cures the noise. If so, you can do a permanent seal w/spray foam sealer from H.D. or Lowes.
Baja-tested '08 2-slide 36'
Alpine: The Ultimate DIY'er Project