It is an Inter Club Challenge hosted by the XR-XY, ZA-ZD Falcon Fairlane Club of Victoria. Clubs involved include The Ford Coupe Club, Ford Performance Club and the Falcon G.T. Club of Geelong. There may be other Clubs members and guests going,but I can't remember off the top of my head. So far as I know visitors are welcome to come for a look. For the rest of the info check Botch's thread on Winton.