Porsche 981 Cayman GT4 Rear Diffuser 2015-2016Diffusers work in conjunction with other aerodynamic components of a car to help produce downforce. Because a car displaces air as it moves forward, the air molecules in the rear of the car get disrupted causing a vacuum of low pressure air. To help channel the high speed air flow coming from underneath the car, diffusers redirects the high speed air flow to transition smoothly transition into the low pressure vacuum in the rear. This encourages a