yes IIRC, the outer of the two tailpipes has a valve. in comfort and eco pro it's closed unless the engine is at high revs...then it's open. in sport/sport+ the valve is open all the time.Will my 428i GC have exhaust valves that activate in Sport mode?
but as an ex-owner of a 428i and then a 440i (and now with the power and sound kit), the N20 engine with the stock exhaust isn't very loud or poppy