High Quality Content by WIKIPEDIA articles! The 1984 Castrol 500 was an endurance motor race staged at the Sandown Park circuit in Victoria, Australia on 9 September 1984. The event was open to Group C Touring Cars, competing in two engine capacity classes, Up to 3000cc and Over 3000cc. It also included a class for Group A cars which were to replace Group C cars in Australian Touring Car racing in 1985. The race, which was held over a distance of 503 km, was Round 3 of the 1984 Australian Endurance Championship.