look for a local sheet metal shop, show them the picture, they might be able to help. i think i could make that..well, ive never tried to make something like that exactly, but i bet i could make that. its just a medium gauge metal with bends, what appears to be some 1/2" rod, and some hardware to hold it all down. i dont know if something like that needs to be safety stamped though, if its for a track.
and OH MAN those rear tires are in pain