Until 1966 the famous Rolls Royce ‘FAB1’ was a model starring in many of the Thunderbirds TV programmes and in both the films. A full-sized replica of FAB 1 was built to transport writers-producers Gerry and Sylvia Anderson to the premiere of the second movie ‘Thunderbird 6’ * in London. It was constructed by the company Toby Baxter Contracts under Sylvia’s supervision and not by Brains or Rolls Royce.
* In the linked article below, it incorrectly says that the premiere was the first movie ‘Thunderbirds are Go’. (see comments)
Petrolheadism, a well known motoring blog, has the fascinating story of what happened to this model and where it is now.