Welcome to the Valvetronic Designs cat-back exhaust system for the F87 M2C platform, or in other words, the solution to the S55 sound problem. For years, enthusiasts have wanted to find a solution to the buzzy and raspy sound these cars produce from the factory. As the M2 Competition has the same problem as its big brother, we had to develop a solution. Our mission has been to find this hidden sound and allow all F87C owners to enjoy it. This full catback comprises a 2.75" equal-length midsection with an H pipe configuration. After traveling through the H-pipe, the exhaust is combined into a 3.5-inch axle back. This combination helps smooth the exhaust tones, providing a delightful sound through the entire rev range. When operating with the valves open, the exhaust gases exit unrestricted out of the passenger side exhaust tips. With the valves closed, the exhaust passes through our quad-chambered muffler and out of the driver's side exhaust tips for a lower volume experience. It is very well suited to daily driving and does not alert the Karens. This system mounts up to factory mounting points and is a direct bolt-on. It's time to make your M2 Competition sound like it always shoul