I heard one of the commentators during the ToC mention it. He said it enforces mouth breathing, and causes greater oxygenation during warm up, or something similar.
Me, I'm going with the story that Levi's mom was trying to get him to quit picking his nose, again. Either that, or some kind of molotov cocktail that, when lit, will cause his brain to explode.
Johan: "Ride fast, Levi, or ve light der fuse!" [evil laughter]