I think I have confirmed that my car (thus, likely any 2008 or newer 550 with the Sport Package) does not have this valve. I am guessing that the valve is removed as part of the special exhaust tuning that BMW claims is included with the Sport Package. So, this mod is already part of our car model.
Anybody else with a 08 or newer 550, please chime in.....
2008 550i, Carbon Black, Black Dakota, 6MT, Sport Package, Nav, Logic7, Comfort Access, Cold Weather, Folding Rear Seats, iPod SOLD, but not forgotten