The only truly Welsh car manufacturer, Gilbern is also one of the few firms to graduate from kit-cars to completed production vehicles, though all used the same production method of a glassfibre body over a steel tube chassis. The Gilbern name is a combination of its two founders, Giles Smith and Bernard Friese.

Early GTs were based on BMC mechanical parts, but over the years the company used more and more parts from the cheaper source of Ford, starting with its V6 engines for the Genie and Invader models. By the Invader III all mechanical parts were stamped with the Ford logo. The energy crisis killed the company off in 1974.