APR Catback Exhaust System | Audi RS4/RS5 (B9) (18-25) (CBK0037)

The APR Catback Exhaust System is a complete, high-performance exhaust upgrade designed to run from the catalyst to the rear of the vehicle. It is engineered to improve performance, enhance exhaust sound, and add a distinctive RS-inspired appearance with diamond black oval exhaust tips. APR uses premium materials and advanced manufacturing techniques to create a system intended to withstand harsh conditions and deliver lasting performance. At wide-open throttle, the exhaust produces a bold, aggressive growl. The system is also reported to deliver gains of 9 horsepower and 15 ft-lb of torque to all four wheels, combining a more engaging sound with measurable performance benefits.

This APR catback system is described for the Audi B9 RS4 and RS5; the product title identifies fitment for the 2018–2025 Audi RS5 (B9). The source does not specify engine details, installation method, or additional compatibility requirements, so confirm vehicle fitment before purchase, particularly for RS4 applications. The system replaces the exhaust section from the catalyst back and includes RS-style diamond black oval exhaust tips. No other included components are specified. Intended for drivers seeking increased performance, a more pronounced wide-open-throttle exhaust note, and a distinctive rear appearance, it is presented as a complete vehicle-length catback solution.