I have an 06 c90...only have 1 airbox...never knew there was 2...have looked at other pics of 06 c90's and don't see any with 2...do see some without one on the right side...any pics of what you presently have?
That's probably what it is. That didn't occur to me since this was bought out of stateWelcome from Kennesaw GA!
That second air box could be a California emissions thing and not exist on bikes sold outside of that area. I have no idea though, just guessing.