Active Autowerke E9X M3 Signature X Pipe & High Flow CatsActive Autowerke is proud to release the highly anticipated Signature Track Pipe with X Pipe and Connecting Pipes for the BMW E9X M3. This exhaust system was designed and engineered to work with most after market exhaust systems mufflers on the market today without the need to cut, weld or modify anything. It is a true bolt on that can be performed by most. This system uses a free flowing 100 cell high flow catalytic converter. Active Autowerke is