Gloucester, had to really sort this “Meaning” of “Concept” / “Prototype” Cars Out. This is what I found and now to me correctly is the Concept followed by the Prototype - worth a find and read for a better understanding - Dave
“A concept car is a representation of what was planned (concept), but it isn’t a true working model, just shows what it would look like.”
A concept car (show vehicle or prototype) is a car made to showcase new styling and/or new technology. They are often shown at motor shows to gauge customer reaction to new and radical designs which may or may not be mass-produced.
Concept cars never go into production directly. In modern times all would have to undergo many changes before the design is finalized for the sake of practicality, safety, regulatory compliance, and cost.
A "production-intent" prototype, as opposed to a concept vehicle, serves this purpose.
Concept cars are often radical in engine or design. Some use non-traditional, exotic, or expensive materials, ranging from paper to carbon fiber to refined alloys. Others have unique layouts, such as gullwing doors, 3 or 5 (or more) wheels, or special abilities not usually found on cars. Because of these often impractical or unprofitable leanings, many concept cars never get past scale models, or even drawings in computer design. Other more traditional concepts can be developed into fully drivable (operational) vehicles with a working drivetrain and accessories. The state of most concept cars lies somewhere in between and does not represent the final product. A very small proportion of concept cars are functional to any useful extent, some cannot move safely at speeds above 10 miles per hour (16 km/h).
A concept car is typically a unique “one-off” effort to explore different ideas to generate conversations and discussions that help to shape the future development of cars. They are often incomplete, impractical, and rarely evolve into an actual production vehicle. There is little concern for manufacturability, fabrication costs, reliability, safety, performance or legal status for driving on public roads.
“A prototype car is a working model of a concept car, which actually WORKS, the design is optimized with the working elements like engine, electricals etc.”
A prototype car is typically an “in progress” design for a car that is intended to ultimately go into production. There may be some experimental aspects on the prototype to evaluate whether the new technology is ready to be released into production. The parts that go into prototype cars are mainly existing mainstream parts (or a variation) — with a good understanding of their manufacturability, performance, supply, and cost. The prototype basically allows the manufacturer to confirm that they have a design that is ready to go into production, or to identify what details still need changes. There may be several prototype iterations, with the earliest iterations having a higher percentage of parts made by “one-off” custom fabrication methods.
Toward the end of the prototype process, the parts will be made largely with production ready processes and nearly identical to the production vehicles.
