Dinan Free Flow Axle-Back ExhaustDinan engineers designed the F55 MINI Cooper S exhaust to improve exhaust flow by reducing back pressure, resulting in increased power output and a great sporty sound that is civilized when you want it to be, and pleasantly aggressive under hard acceleration. Like all Dinan exhausts, our F55 Free Flow Axle Back Exhaust is engineered to combat low RPM drone so the cabin of the vehicle is still intimate and not drowned in an excessively loud tone. The