Simpson Design is an American boutique coachbuilder and custom sports car manufacturer founded in 1998 by designer and mechanic Jim Simpson. Operating from Clinton, Washington, the company is known for hand-built, bespoke sports cars that combine classic European styling with modern reliability. Many of its creations use the Mazda Miata as a mechanical foundation, offering a dependable platform for uniquely sculpted fiberglass or steel bodywork, custom interiors, and one-off detailing. Simpson’s cars have been showcased at events such as Concorso Italiano and the Pebble Beach weekend, earning recognition among enthusiasts for their craftsmanship and originality.

Notable projects include the Italia series—sports cars inspired by mid-century Italian coachbuilding traditions—the Blue Ray concept cars, and the Manta Ray, a Miata-based roadster evoking 1950s and 60s Bertone and Michelotti designs. Each vehicle is built through a highly artisanal process that begins with sketches and clay models, progresses through hand-shaped wooden bucks and steel forms, and culminates in the creation of custom panels, glass, and interiors. By focusing on timeless aesthetics and individualized builds, Simpson Design has preserved the fading art of coachbuilding in the modern automotive world.