Upgrade the sound of your BMW M3 & M4 , eliminate the back pressure from your stock midpipe and gain up to 18 whp and 30 wtq! The MAD S55 single midpipe is guaranteed to fit on the BMW F80 M3 & F82 / F83 M4. The exhaust brace is included with every midpipe for a hassle-free install and spot on fitment. Features: Smooth bends for maximum airflow without any drone Up to 18whp increase on the stock turbos, even more on upgraded turbos Lifetime warranty on defects and fitment 90 day return period All orders ship in 1-2 business days Spot on fitment Fitment: 2015-2019 BMW M3 2015-2019 BMW M4