BMW E9X GEN 2 SIGNATURE REAR EXHAUST N52 | 325 328I BY BMW TUNER, ACTIVE AUTOWERKE11 021 Active Autowerke BMW Gen 2 Signature 328i Exhaust N52 Performance Optimal power, performance and sound are the core values of our Active Autowerke BMW 328i exhaust system, designed to fit BMW 325i and 328i E9X N52 models. A free flow design and beefy 80mm dual exhaust tips allow 35% to 40% more exhaust flow than the stock BMW 328i exhaust system. The increased flow minimizes back pressure, resulting in substantial HP and torque gains. The