Windblox - Wind Deflector for Mercedes SLK R171 Deflector This is the number one rated wind deflector by WindscreenReview.net. Prevent noise and turbulence in the cockpit when driving top-down; causes no glare Warranted for life + 30 day trial period (with free shipping back from US addresses). Made for speed - this Mercedes SLK R171 wind deflector is rated for usage up to 150 MPH. Wind deflector never yellows from accumulated sun exposure. Made from premium double sided AR Polycarbonate, the best available material for this application