Twenty motor car transports were built in 1964. The class was given as MLX and the numbers were 1 to 20. The bogie vehicles were built with skeletal sides.
The traffic was for GM-H ( Holden ) cars between Melbourne and Adelaide.
In 1967 the class was altered to ALX_ 23 to 42. These ALX conversions were very distinctive. They retained the skeletal sides and the horizontal steel safety strips along each side.