A funny conversation

Celest: That is a really big car (a Toyota Alphard next to us).

Nigel: Mummy, is that the biggest car in the world?

Celest: No.

Nigel: Then what is the biggest car in the world?

Mummy: I don't know - we have to ask Daddy to check.

Nigel: I know, it a bus!

Shannon: Is it Bus (Buzz) Lightyear?

Nigel: Huh? Bwhahahahahahahaha.