2016-2018 Nissan Altima - STILLEN Rear Diffuser [Matte Black] - KB13158MBFeatures & Benefits: Diffuser acts as an expansion chamber to manage the air as it exits from underneath the car Smoothing this transition reduces turbulence and drag improving air flow underneath the car. Aggressive styling sets your Nissan Maxima apart from boring stock Widens the look creating attention to the rear bumper adding a sexy and sporty look Compliments the factory exhaust cut out nicely Works best with cars that have a rake angle.