The Rogue Engineering exhausts designed for M-series are dyno-proven to make power while complimenting the vehicle with sound. Designed with BMW M's high-revving engine concept in mind, these exhausts for your M car will be the envy of all to hear, while you enjoy some increased power. Free up power, save weight and improve the sound of your BMW with our exhaust systems. All systems are made from 100% T-304 stainless steel for longevity and great looks.