Upgrade your 2025+ BMW M340 with the MAD BMW B58 Gen 3 "Fat Boy" 5.0" Catless Downpipe—the ultimate performance upgrade designed to unleash the full potential of your engine. Crafted from premium-quality 304 stainless steel, this larger-diameter 5.0-inch downpipe offers superior airflow, delivering enhanced horsepower, quicker turbo response, and noticeable torque gains. The increased diameter of the "Fat Boy" downpipe sets it apart from our standard catless models by providing a deeper, richer, and significantly more aggressive exhaust tone. Precision-engineered welds and exceptional craftsmanship ensure perfect fitment, durability, and peak performance for enthusiasts demanding maximum results. Transform your BMW M340's driving experience by choosing MAD's top-tier downpipe, designed specifically for drivers seeking ultimate airflow and a sound profile that commands attention. Features: Premium 304 stainless steel for superior durability Expanded 5.0-inch diameter for unmatched airflow and performance Deeper, richer, and more aggressive exhaust tone Improved horsepower and torque compared to standard catless downpipes Precision craftsmanship and perfect bolt-on fitment Ideal for high-performance builds and enthusiasts seeking maximum results