An Automotive Design Engineer
Jay Ohrberg designs and makes custom cars under the name "Hollywood Cars"
a Modist
this person is called an architect
BMW became famous for their high quality cars, and their designs.
software developer
You might want to check out. - Industry Design(er) - Automotive design(er)
a person who designs homes is a called an architect
pinninfarnia
A mechanic
A Car Painter
Japan.
A number of cars owned by the same person or company would be called a fleet of cars.