James Corden’s massively successful ‘Carpool Karaoke’ saw its most star-studded edition yet this week, as main guest Gwen Stefani was joined by both George Clooney and Julia Roberts!

The latest instalment of the viral favourite, broadcast on Wednesday night’s ‘The Late Late Show’ (May 4th), saw Corden pick up 46 year old Stefani and they rattled through both her old and new hits as they drove around Los Angeles.

Firstly, they belted out ‘Don’t Speak’, the anthemic breakthrough hit for Stefani’s former group No Doubt way back in 1997 which was a chart-topper around the world.

Gwen StefaniThe resurgent Gwen Stefani was James Corden's latest guest in 'Carpool Karaoke'

Chatting about her new album This Is What the Truth Feels Like and her new relationship with Blake Shelton – whom she described as “like a facelift”! – they also moved on to recent single ‘Used to Love You’, her 2004 hit ‘Rich Girl’ and 2006 smash ‘The Sweet Escape’.

More: Gwen Stefani and Blake Shelton to perform duet on ‘The Voice’ next week

However, Corden suddenly realises he needs another two people in his vehicle to use the carpool lane, and as he reaches for his mobile phone, he says: “I know. This guy, he’s got nothing to do.”

The next moment in the video, in climb two pieces of bullet-proof Hollywood royalty in the form of George Clooney and Julia Roberts – both coincidentally promoting their new movie Money Monster.

Then, in a moment sure to become one of the most memorable in ‘Carpool Karaoke’ history, they both sing along loudly to Stefani’s ‘Hollaback Girl’ before moving on to Queen’s ‘We Are the Champions’.

The segment has been wildly popular in its first year since British star Corden took over the ‘The Late Late Show’, with over one billion YouTube views for its combined videos and over 74 million for Justin Bieber’s episode alone. Plans were announced earlier this year for it to become a half-hour stand-alone special programme franchised out to other networks, with Corden as executive producer.

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