The "Late Late Show" is airing from London this week, but Corden went up to Liverpool to take a drive with McCartney in the former Beatle's hometown.
Corden told him: "Your music is so full of positivity and joy and a message of love and togetherness, I feel like it's more relevant today than it's maybe ever been".
But perhaps the most powerful moment happens when McCartney and Corden sing "Let It Be" in the auto and Corden chokes up with tears.
As they look around, Sir Paul says one of the downstairs rooms is where "me and John would often come to rehearse or to write".
The Late Late Show host was joined by the singer as they drove past famous Beatles landmarks.
Corden said it was the "most attractive story" he had ever heard, before singing a teary rendition of the song.
McCartney, who is now 76, is clearly not slowing down any time soon: he's releasing a new album in the fall, called Egypt Station, and just put out two new songs.
As he led Corden through the home (even sitting down at the piano to sing "When I'm 64"), he told Corden how his father had critiqued "She Loves You", suggesting they replace the "yeah, yeah, yeahs" with "yes, yes, yes". As he and Corden began singing the classic song, Corden got visibly emotional, tearing up as he harmonized with the music legend.
Paul McCartney and James Corden visit Penny Lane in Carpool Karaoke. "I'll never ever forget it". "I remember me and my mom and dad". However, the best part for McCartney was returning to the home where he lived out his teenage years and, more importantly, where The Beatles got their start.
Later, he performs some Beatles hits after appearing from behind a curtain in a pub.
