She ain't no holla back gurl!

Everyone's favorite singer Gwen Stefani hopped into James Corden ride's and had a sweet escape with the funny Brit on the latest edition of The Late Late Show's "Carpool Karaoke." And as if the No Doubt's presence wasn't a big enough get -- George Clooney and Julia Roberts got in on the fun too!

Now that's one star-studded car!

At the beginning of the fun-filled journey, Stefani and Corden sang a number of hits, including No Doubt's "Don't Speak," and her solo songs, "Used to Love You," "The Great Escape," and "Rich Girl."

The two banter and joke and we realize why we love both of the lovable stars oh so much!

But the real b-a-n-a-n-a-s part is when Corden made a call to a pal and before long the Cloones, followed by the the oh-so beautiful Roberts, were all singing together. Too Cute!

The good-looking group sang "Hollaback Girl," before launching into a rousing rendition of Queen's "We Are The Champions."

Yes -- they really all the champions ...

FYI: Clooney and Roberts are starring together in the upcoming film Money Monster -- and clearly they wanted to have some fun while promoting their new movie.