The 2014-15 Audi R8 4.2L Exhaust Suite sets a new standard. Beyond the handcrafted detail that is standard for every AWE exhaust, this one packs a little something special: The R8 4.2L Exhaust incorporates a proprietary mechanical valve system that controls sound volume: Under part throttle and idle, valves route exhaust gasses through a central muffler, keeping sound tame and drone free. At 3/4 throttle application and more, the valves open and the system is unleashed – going into "straight pipe" mode. An in-cabin mounted electronic SwitchPath™ Remote toggles the mechanical valves between "normal" and "straight pipe mode." Practical. Important notes: - These exhaust products are for racing use only. - Customers with S Tronic cars must also purchase the Audi R8 S Tronic Exhaust Fitment Kit. If you have an R8 4.2L and you're looking to make one of the most meaningful evolutions available, this is your move.