Whats the go? surely with the Veyron rear wing and certain cars air brakes, it wouldn't have been a problem to implement the air intakes raising at high speed...
The vents will go up only on traffic jams, when the engine gets too hot.
If the car reaches certain speed the vents will close, to reduce drag.
Makes sense to have it closed all the time, as we don't have variaton on the engine's temperature.