James Corden’s The Late Late Show Carpool Karaoke Primetime Special received the diva treatment as Christina Aguilera joined the talk show host to sing some of her greatest hits. And while they were singing her seminal hit Dirrty, Melissa McCarthy popped up from the backseat just in time to spit the rhymes of Redman’s portion of the song. While on their song-filled ride (before McCarthy’s cameo), Aguilera and Corden gave the late night talk show host a lesson in diva…