BMW M Performance valve exhaust silencer system for the BMW X4. (press.bmwgroup.com)
In Sport mode, the M Performance valve exhaust silencer system is approved for operation on public roads. (press.bmwgroup.com)
Combined with the stainless - steel exhaust silencer system with the two striking tailpipes and suspension springs, they render the ABT RS6 dynamic in a discreet fashion. (abt-sportsline.de)