In 1936/1937, six Dodge cars were built under licence by Richard & Sons, Adelaide. These cars were equipped with rail wheels.
They were described as 'Passenger and Mail Motors' officially but at the time of delivery they were placed into the Rail Motor group and lettered RM. The cars were numbered 70 to 75.
Traffic was on light use branch lines and later one car became an inspection car for officials.
The vehicles were removed from service and scrapped between 1953 and 1958.
One car was found and sat at the ARHS Museum, Newport for several years during the 1980's. It is currently being restored.