Concept vehicles or show vehicles are made to showcase new styling and/or new technology. They are often shown at automotive shows to gauge a customers reaction to new and drastic designs which may or may not be produced. Because of safety, regulatory compliance and cost, concept cars never go into production directly; there are many changes that happen before the design is finalized. Concept cars are often radical in engine or design and sometimes use exotic materials that can range from paper to carbon fiber to refined alloys. Others may also have unique layouts, sucha as 3 or 5 (or more) wheels, gullwing doors or special abilities not usually found on cars. Because of these designs, most concept cars don't make it past scale models, or even drawings in computer designs.
When cars make it past the first stage of concept, they enter the inoperative "mock-up" stage, where they are created using wax, clay, metal, fiberglass, plastic or a combination of materials. If the vehicle is operative, the drivetrain is usually borrowed from a production vehicle within the brand. If a concept car doesn't make it to production and the car's useful life is over, the cars are usually destroyed. Some though are kept and either put into the company's museum or hidden away in storage.