BMW ALPINA B3s exhaust flap does work.

B3Sのエキゾーストフラップ、動画撮影に成功しました。 詳細は、「みんカラ」で!

More Videos...

BMW E36 328i exhaust silencer flap operation

Capristo RS5 exhaust flaps

e90, e92, e93 BMW Exhaust Flap Rattle Fix
This happens to a large amount of these cars. If you drive a e90, e92, e93 or maybe other ones, this will definitely help you at one point. This mod also makes your Exhaust sound very nice (a tiny bit louder)

2001 BMW 330Ci Exhaust flap operation - MS43 Siemens DME