Active Autowerke BMW E46 M3 HeadersActive Autowerke BMW E46 M3 Header The Active Autowerke BMW E46 M3 Header is designed to increase exhaust flow without losing power which can sometimes be a tricky proposition. These headers are developed to create optimum flow and eliminate restriction that rob much desired horsepower. Following the famed BMW E46 M3 CSL headers, each individual header runner of the Active Autowerke header is cut to au00a0matched equal length to ensure a consistent