KYOSTAR Valved Catback Exhaust System w/ Bracket for BMW G87 M2 S58 3.0T The KYOSTAR Valved Catback Exhaust System is specifically developed for the 2023+ BMW G87 M2 equipped with the S58 twin-turbo engine. Featuring an electronically controlled valve system, it provides a refined exhaust note during everyday driving while delivering an aggressive performance sound under acceleration. The optimized exhaust routing improves flow efficiency and enhances the driving experience