When car manufacturers design a new automobile, they develop requirements, conduct research, draw designs, make scale models, test scale models in wind tunnels, computer model their ideas, build full-scale prototypes, test them, and iterate the designs – all of this before putting them into production. What they don’t do is go right from drawing them on a piece of paper or having a pocketful of highly subjective ideas to putting them into production.
So they don’t base their decisions on a paper prototype or a list of personal ideas. Why? Because a car is a 3 dimensional experience. It is an experience of the senses. It is an interactive experience. You really need to understand it before you put it into production. Mistakes carried through into production would be costly.