These are awesome, and yes, I wish I could buy one, too. Cypher shows off these ribbons she made over on livejournal, and says that whenever she drives around with the Horde one on her car, fellow Hordies scream "For the Horde" at her as she drives by. Sounds about right! For the Horde!
But she says she made them for her and her roommate-- does she keep them both on the same car? I don't know how the whole "Blizzard-created logo" copyright thing would work (and I'm not quite down with putting stickers on my car), but selling both of these as magnets would be a great idea. Very awesome.