From what I recall from old posts (not Mazdaspeed 6 related) the roof wind deflector doesn't do anything. imho, it's ugly, fwiw.
Thanks, sounds like I'm better off without it. The dealer did not install them on any of thier stock; it could be there's an honest employee ordering for their lot who hasn't been found out yet.It's (the wind deflector) a dealer "pack". One of those things a dealer uses to make an additional profit on a new car. It probably costs the dealer less than $20 and they charge you $100 or more.
Aside from looking dumb they do little or no good.