Audi RS5 B9 Cat-back Resonated Exhaust System by Milltek Sport (2017+)Milltek Valved Exhaust System specifically designed for Audi B9 RS5 2. 9 with a selection of Polished, Cerakote Black, Titanium and Burnt Titanium trims. With in house production and engineering in the United Kingdom, Milltek have been designing and developing exhaust systems for over 32 years. This experience has helped put Milltek on the map when it comes to performance exhausts, with offerings that range from Audi Volkswagen to Porsche, BMW, and