The Ross 500 was constructed in 1953 by Ed Ross of South Australia. Little is known of the car except that it was powered by a Triumph engine and, as can just about be made out in the photo below, it was well-built. It's debut may have been at the Collingrove hill climb, October 1953.
The car was eventually rebuilt, but results are scarce. We only have an appearance at Port Wakefield in 1958.
If anyone has any more details or photos, please get in touch.