The only roadworthy Chitty Chitty Bang Bang from the 1968 film is coming to auction next month with an estimate of $1m to $2m.

Profiles in History is selling the vehicle at its Hollywood Memorabilia Auction in Los Angeles on May 14 and 15.

Six cars were made for the film, and many have appeared at auction. But just one is fully functioning and roadworthy: the 1967-built GEN11.

Although now lacking its flying gear and floatation equipment, it will be of considerable interest to classic car investors and fans of the film. 

Michael Jackson once tried to buy the car for $1m

Featuring an alloy dashboard from a world war one British fighter plane, the car was conceived by production designer Ken Adams and built by the Ford Racing Team.

The car once competed in charity races throughout the UK and remained under the careful ownership of Pierre Picton in England for more than 50 years.

A non-road going version sold for $505,000 in 2007.