Although it may not have been what James Mangold had initially intended, the director was open to his actor’s suggestion and they gave it a shot. In addition to proposing that Ken Miles ask Peter to get in the car with him in the first place, Christian Bale also came up with their interaction after. Christian Bale thought to sing a song about being happy that he knew from his childhood. It was fitting given his character’s personality and the fact that he had just won a race. Fortunately, Noah Jupe actually knew the song because he is English as well, so the two could sing the song together, really coming off as father and son.