WATCH: James Corden's Newest Carpool Karaoke Features Two Extremely Famous Special Guests!

Not only did Gwen Stefani join the TV host, there were also two A-List actors in the back seat!

We're all familiar with James Corden's Carpool Karaoke segment on his Late Late Show in the States at this stage but this one has to be one of the best yet!

This edition of the feature sees No Doubt's Gwen Stefani helping James get to work while having a chat and singing some of Gwen's classic songs. The pair belt out No Doubt's iconic 'Don't Speak' as well as Gwen's solo songs 'Sweet Escape', 'Rich Girl' and newest track 'I Used To Love You' .

James asks Gwen what the secret is to her never ageing and tells her that she is a female version of Benjamin Button! Gwen gives a very interesting answer to the question!

Gwen is said to have taken a shining to emojis and James asks her to try to recreate certain faces while in the car.

Soon after James and Gwen come to the HOV4 lane which means you need at least four people in the car to drive in the carpool lane. James calls a friend to ask if they'd help him out and join them in the car. This is when we meet the first of the two special guests, the one and only George Clooney! The fourth star to hop into the car after a call from George is none other than Julia Roberts!

Gwen, James, George and Julia then sing along to Stefani's huge hit 'Hollaback Girl'.

James asks George and Julia what their favourite lines were from their films. James doesn't please George when he quotes Julia Roberts in Notting Hill “I’m just a girl standing in front of a boy, asking him to love her”. George responds: “Now I’m not sure I want you to drive.”

They finish their journey with a passionate rendition of Queen's 'We Are The Champions'.

Watch it for yourself and enjoy!