things with wheels that are cool
Those were specially designed for the Vega to minimize shipping cost by maximizing space efficiency. Doesn't usually work in short term plans. It was largely a publicity stunt and was used in advertisements.
The Vert-A-Pac car, designed by the Southern Pacific RR and GM for toting sub compacts like Vegas in 1969...about 200 were eventually built. The pix pretty much say it all as for loading/unloading. Great find...
...forgot to mention that a set of locks was built into the car that caught onto securing points built into the vehicles. They had plugs installed to keep the fuel in the tank while transported.