The Akrapovic Sound Kit for selected 2021+ BMW G87 M2, G80 M3 and G82 M4 exhausts lets drivers switch between quiet and sportier modes from the cockpit. Using a receiver to drive actuators that open or close exhaust valves and a Sound Remote Controller, the kit alters system acoustics; note that installing the Sound Kit voids the existing ECE type approval.
Akrapovic 2021+ BMW G87 M2, G80 M3 & G82 M4 Sound Kit