Caractacus is the widowed father of two kids who is an eccentric inventor that makes a few interesting "tweaks" to the car that is known as Chitty Chitty Bang Bang. In a 1967 interview with film critic Roger Ebert, Dick previewed the film this way: "My next movie, believe it or not, is going to be based on a novel by Ian Fleming. It'll be called Chitty Chitty Bang Bang... It's based on Fleming's only book for children. It's about this ancient old automobile that has magical properties. When it starts up, it goes chitty chitty bang bang. And it can fly. I play a nutty inventor, and there's a girl in it with a typical Fleming name: Truly Scrumptious. She's played by Sally Anne Howes."
By that time, of course, he was already a massive star. His pre-Chitty credits include his acclaimed role on the TV sitcom The Dick Van Dyke Show, and films like Bye Bye Birdie, What a Way to Go, Mary Poppins, and Divorce American Style.
He was actually reluctant to do the film, as he revealed in his autobiography My Lucky Life in and Out of Show Business, "The movie’s producer, Albert 'Cubby' Broccoli, known for his tight-fisted control of the James Bond movie franchise, desperately wanted to re-team Julie Andrews and me after the success we’d enjoyed with Mary Poppins. I can’t speak for Julie’s reasons, but both of us turned him down. I thought the script had too many holes and unanswered questions. However, each time I said no, Cubby came back with more money. I’m talking serious money — more than seven figures, which in those days was mind-boggling, plus a percentage of the back end, which I never counted on. So I finally agreed."