Hesitant at first, the cast members then joined in, with Cox exclaiming, "I've always wanted to do Carpool Karaoke."
But when the singalong came to an end and Corden pulled the golf cart to a stop, he forgot to put the brakes on and it went rolling in reverse amid uproar from the cast.
But after panicking for a few minutes, the cast members all disembarked without injury. They then headed into the Central Perk set as Corden nervously told the camera how he genuinely believed he'd been about to kill pop culture's favourite friend group.
Safely inside, Corden continued the conversation, with LeBlanc offering how he was affected by returning to the set with his old buds.
"We've had a lot of laughs. Some of it made it on camera, but the funniest stuff that happened between us, that never made it to TV, those are the memories we keep talking about," he said, looking to his co-stars for agreement. "Remember when this happened. Remember when that happened. America, or the whole world, never saw some of that stuff."