Block Substantial Turbulance while driving with the top-down. Prevent hair from swirling about at freeway speeds. Quiet Cockpit: Talk on your cell phone and converse with the passenger next to you without strain. Lifetime Warranty with 30 day trial. We stand by our product. Abrasion Resistant Material: will stay clear for the lifetime of your car. No Squeaks or Rattling: Unlike other wind deflectors, this windscreen stays securely in place when mount, eliminated novice-induced vibrations. This is the #1 Ranked BMW Z4 Windscreen. For all of the reasons you purchased a convertible, this windblocker will make all of those reasons come alive.