You mean window visors right? EBay has them and I can't remember if they are in-channel or not. But I don't like the look of them on some 5's depicted around here. Of course you don't want that buying medium either.
I just ordered a set from a guy on MPVClub who goes by mazdaspeed02mpv for $35 shipped in the US. I've seen these installed on two 5's and I really like the look of them.