EXHAUST SYSTEM E600NA prototype 2ed Posted on Feb 08, 2019 Checking the exhaust sound of prototype 02 by opening and closing the exhaust flap with an electronic actuator system. Racing sound when open Silent mode when closed Still some sloshing sound, so reworked. Share this:. Share on Facebook Tweet on Twitter Pin on Pinterest Previous Nov 09, 2018 Exhaust BMW F87 M2 Competition Next July 09, 2019 EXHAUST SYSTEM E600NA prototype 6th