Dinan's free flow Axle-Back exhaust for the 135i Coupe and Convertible improves 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 harder acceleration. 100% stainless steel construction and exacting specifications ensure that the system fits correctly using the factory hangers and will resist corrosion for years to come. The design reduces overall weight as well and features 3.5'' polished stainless, or ceramic black, tips for a tasteful high-performance look.