Dinan Free Flow Axle-Back ExhaustDinan engineers designed the BMW 330i 430i 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 330i 430i Free Flow Axle Back Exhaust is engineered to reduce low RPM drone so the cabin of the vehicle is still intimate and not drowned in an excessively loud tone. The