Originally Posted by Epacy
So, your saying that the hole isn't open into the engine?
No, of course it is. But it's not there to vent the engine, it's just to make the bonnet (hood) look better. If there wasn't a need for the one intake then there wouldn't be a vent there at all.
If it does help keep the engine cool then that's purely an indirect consequence of the need to make the design look more symetrical.
The M5 and M6 don't have vents on the bonnet, and the E46 side grills were only there for show (harking back to the 507).
Rumour is that the E92 CSL will use both intakes for extra performance.