If you thought Gwen Stefani's episode of "Carpool Karaoke" on The Late Late Show with James Corden was going to be a standard drive-by promotional appearance... think again. The pop star and No Doubt leader picked up Julia Roberts and George Clooney while driving with Corden, and belting out some of her most memorable tunes.

The first half of the episode is very lively, with Stefani explaining how she stays so young and interpreting her favorite emojis in between songs like "The Sweet Escape," "Rich Girl" and "Don't Speak." But then Clooney comes in, and so does Roberts, and "Carpool Karaoke" becomes... well, a bit more crowded, but pretty great nonetheless.

Watch above as the quartet sings "Hollaback Girl" and Queen's "We Are The Champions." Stefani, who released This Is What The Truth Feels Like in March, sure did Clooney and Roberts a solid by helping them promote their new thriller, Money Monster!