Borla Cat Back exhausts function patented, multi-core and straight-through expertise to unleash secret horsepower. Improved exhaust velocity contributes energy, generating pleasure, gasoline economy and also the unique Borla Sound of Power highly regarded by motoring aficionados all over the place. Each and every device is created of premium austenitic stainless steel, greater than T 400 collection knockoffs, to offer you the best possible on overall performance durability. Features M3 Coupe Convertible - 08 10 4.0L Cat back process Quad exit, split back 2.5 in. piping diameter Aggressive audio level Single inlet and also twin outlet muffler arrangement Quad 3.5 in. polished stainless-steel suggestions...