AWE Tuning Audi R8 4.2L Coupe SwitchPath Exhaust (2014+)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