The WMA was a class of two deck motor vehicle wagons built on the frames of WF class flat wagons. converted to class WMA to carry motor cars in 1968. They were all converted back to class WF in 1975. The WMX class were double deck car carrying wagons. A total of thirty were built in two series. With the loading gauge no obstacle and the light weight of the load, conversion to a triple deck car carrier was an obvious improvement. WMX 34039 was the prototype conversion and became class WMB in 1977. It was reclassified WMGY in 1980. In 1993 it was converted to WMGF. From 1979 the WMX were reclassified to bring them into line with the ROA standards and became WMFX. This was complete by 1983. After the success of the conversion of 34029 more were required. The vehicles selected for the conversion were the remaining second series WMFX wagons which became class WMGF. All were converted in 1989 the WMFX was brought into line as a WMGF in 1993. In 1994 all 10 wagons were hired to NRC as RMWY. However two were reclassified RMGY in the same year (possibly in error).