Christina Aguilera Out-Divas James Corden In Carpool Karaoke With Surprise Stowaway Melissa McCarthy -- Watch!

Christina Aguilera is gearing up for a return to the spotlight with new music — and she is fully prepared to do things the 2018 way.
That means enthusiastically giving James Corden diva lessons on Carpool Karaoke after Melissa McCarthy pops up from the back seat to sing the Redman rap on Dirrty! Watch (above)!