ACTIVE AUTOWERKE E9X M3 SIGNATURE X PIPE WITH GESI ULTRA HIGH FLOW CATS11 018 Active Autowerke is proud to release the highly anticipated Signature Track Pipe with X Pipe and Connecting Pipes with GESI G Sport cats 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. Active Autowerke is able to improve on the factory X Pipe design