George Clooney, Julia Roberts and Gwen Stefani don’t hold back during car karaoke

Four of the world’s biggest celebrities have come together for a wild car ride with US talk show host James Corden, belting out some classic tunes and scoring plenty of laughs on the journey.

As part of The Late Late Show’s popular segment “Car Pool Karoake”,  host James Corden picked up No Doubt singer Gwen Stefani to “keep him company on his ride to work”.

The two sang some of Stefani’s tunes before they hit a roadblock – realising they can’t use the “HOV 4” lane without two more people in the car.

After a quick phone call, Corden manages to rein in actors George Clooney and Julia Roberts.

It’s not long before the famous foursome burst into a powerful rendition of Queen’s We are the Champions.

Clooney and Roberts also display their impressive knowledge of Stefani’s Hollaback Girl, singing along to every word.

“Ain’t No Hollaback means if guys are on a construction site and they’re yelling at a girl, she’s not going to turn back, she’s not that kind of a girl,” Clooney said, putting forward his theory as to the song’s meaning.

Other Carpool Karoake guests have included Adele, Stevie Wonder, Justin Bieber and Elton John.