Many concept cars are never actually produced for sale but they can give an indication of the ideas the manufacturers are considering for the future and of the design trends that are currently popular.

They also offer opportunities for testing the market and the public appetite for new designs.

The process of designing a new car is a complex and very expensive process to refine the way the proposed new vehicle will look, handle and be engineered and powered.

Despite the many advances in computer technology the process still starts with several hundred sketches. Computer models are not yet sufficient to evaluate a design and the next step once the sketches have been refined to establish how the car will look is to create a clay or industrial plasticine model. The clay/plasticine is a malleable material that can be easily shaped.

Clay model making) for vehicle prototypes was first used by the auto designer Harley Earl in the 1930s. Earl was then head of the General Motors styling studio. The clay model stage in new car development is still used to this day.

Usually the model consists of a frame which is covered with Styrofoam. The clay is smoothed over the foam. Modellers then use various tools to finalise the shape of the car, since changes are readily possible.

Sometimes these prototype models are displayed at motor shows or are used for marketing trials to get a sense of whether they are likely to appeal to consumers before the company goes further in developing, testing and refining a prototype to the point where it will be viable for the production line.

Since the motor industry is highly competitive and the costs and time involved in developing new vehicles is considerable the manufacturers will go to considerable lengths to keep their development work a secret until they are ready for it to be unveiled either as a model or as a prototype or concept car at a motor show or other event.

If it is a clay/plasticine model that is to be used there is a further issue, which is that the material is very sensitive to temperature. Too hot and it will melt, too cold and it becomes brittle and fragile.

This combination of factors means that the vehicles need to be transported very carefully to their destinations in enclosed and temperature controlled transport by people who are skilled in this particular type of transportation.