Usher is one of a long line of pop stars to join "The Late Late Show" host James Corden for "Carpool Karaoke." On Tuesday's episode, the pair sang Usher hits, danced and also performed an unexpected good deed.

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As soon as Usher got into the vehicle, Corden began playing “Yeah!” -- one of the R&B megastar’s biggest hits -- with Corden hitting every word of  the Ludacris verse.

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The duo then took a detour into a parking lot so Usher could teach Corden some dance moves.

After a rousing rendition of “Let It Burn,” they made another unscheduled detour to Usher’s Hollywood Walk of Fame star and give it a “spit-shine” cleaning.

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“I find it odd -- you work all of these years, as hard you can, only to have people walk over you as a star,” the singer told Corden.

The drive then continued, and in the middle of their performance of “OMG,” they spotted a couple of mechanics pushing a Porsche down a street and did what any pair of celebrities would do while filming a segment for a popular TV show -- they got out and helped.

“I had no idea when I got in your car I’d end up pushing cars and cleaning my star,” Usher said before they launched back into their rendition of “OMG.”

Usher - Fast Facts