Sir Michael Caine did Cars 2 for grandchildren

Sir Michael Caine took on the voice of automobile Finn McMissile in 'Cars 2' so he could show his grandchildren what he did for a living.

Sir Michael Caine decided to appear in 'Cars 2' for his grandchildren.

The British star - who voices Finn McMissile in the animated movie - wanted to be able to show the younger members of his family what he did but realised he couldn't show them some of his more adult-themed films.

He said: "When they ask what their granddad does, they can't see him in anything.

"You don't want to say 'Harry Brown'. It's not family viewing. When they offered me the chance to play the part of a car, I was very interested."

The 78-year-old actor also reveals he is one of only a handful of people to have seen the final script for forthcoming Batman movie 'The Dark Knight Rises', with director Christopher Nolan entrusting him.

Michael - who plays butler Alfred in the film, told Empire magazine: "I've read the new Batman script. Chris is the most secretive person. He said to me, 'You're one of only four people who have the end.'

"I daren't say a word about it or else I'll get fired."