So far, the only thing the book and the movie have in common are:

1) there’s an old racing car called Chitty Chitty Bang Bang that can do magical things

2) the owner of the car is Caractacus Potts

3) his children are named Jeremy and Jemima

4) he bought the car with money he made from selling whistling candies to Lord Skrumshush

5) they get stranded on the beach

XD