Fits: 2000 BMW 323Ci 1999–2000 BMW 323i 2001–2006 BMW 325Ci 2001–2005 BMW 325i 2001–2006 BMW 330Ci 2001–2006 BMW 330i Borla140084CatbackBorla Cat-Back And Axle-Back exhaust systems feature patented straight-through and multi-core technology to unleash hidden horsepower. Increased exhaust velocity adds power, driving excitement, fuel economy, and the distinctive Borla Sound of Power respected by motoring enthusiasts everywhere.Borla S-type cat-back exhaust systems feature patented straight-through and multi-core technology to unleash hidden horsepower and produce a more aggressive sound and higher flow. Increased exhaust velocity adds power, driving excitement, fuel economy, and the distinctive Borla Sound of Power respected by motoring enthusiasts everywhere. Each system is built from premium 300-Series austenitic stainless steel, superior to T-400 Series knockoffs (such as 409), to give you the absolute best in performance and durability. Ultra-smooth mandrel bends ensure maximum flow and power, and precision computer-controlled CNC manufacturing ensures an accurate fit. It's just what you'd expect from the world's most experienced (and most winning) exhaust brand.