Diy Wind Deflector Roof Rack . If you like diy options and don’t want to spend the money to buy wind fairing/ wind deflector, there is a simple and easy way to stop the whistling. P38 oem roof rack wind deflector. Angled Maxtrax Wind Deflector Mounting Plate Bracket Rhino Platform from www.kaon.com.au Then i tighten the bolt using an allen key from the outside, which pulls the washer in and squeezes the rubber grommet out against the. Here are a few notes as to how i created my roof rack. I built this wind deflector (fairing) using pvc foam board.