Introducing the APR Rear Catback Exhaust System for the Audi B9 SQ5 The APR Rear Catback Exhaust System for your Audi B9 SQ5 introduces a deeper and more aggressive growl to your vehicle’s exhaust note. The system is a direct bolt on with your factory exhaust system or can be combined with the APR Midpipe Exhaust System for a more refined and more powerful full catback experience! Inspired by the larger center-pipe design of the higher-output RS4 and RS5 models, this system is engineered to boost performance and elevate sound. Crafted from premium materials and built with advanced manufacturing techniques, this system is will withstand harsh conditions and deliver lasting performance. Expect a bold, aggressive growl at wide-open throttle, along with a gain of 5 AWHP and 6 AWFT-LBS or an impressive gain of 10 AWHP and 12 AWFT-LBS when combined with the APR Midpipe Exhaust System! Unmatched Design and Precision Engineering Unlike anything currently available, the APR system starts just after the midpipes but can be combined with our midpipe system to making this a true full-system upgrade. We’ve minimized restrictions with smooth transitions, oversized piping, and a straight-through rear muffler / Helmholtz resonators. Constructed from mandrel-bent T304 stainless steel with a brushed finish and TIG welding throughout, this exhaust system is as durable as it is striking. Installation is hassle-free, thanks to precision-fit brackets, OEM-style slip clamps, and an included upgraded tunnel brace to accommodate the oversized piping. Inspired by RS Performance Like the RS4 and RS5, this system features a reengineered exhaust routing design. It utilizes a dual 2.75” (70mm) midpipes merging through a cast Y-junction into a massive 3.5” (91mm) midpipe, replacing the restrictive factory dual-pipe setup. The exhaust valve is fully integrated with the OEM control system, adjusting automatically to enhance sound during aggressive driving while maintaining a quieter profile during cruising. When closed, exhaust gasses route through the rear muffler featuring straight-through sound absorption technology and when open, bypasses the rear muffler all together. Experience the APR Difference Designed for enthusiasts seeking the perfect balance of power, sound, and quality, the APR Midback Exhaust System for the Audi SQ5 is a testament to engineering excellence. With its performance-driven design and durable construction, this system not only transforms your driving experience but also ensures years of reliable performance.