Howdily Doo!
We’ve already established that the cars in Cars eradicated humans from the planet after deeming us unnecessary (thanks, Lightning and Mater). But that doesn’t explain why different cars have different accents. If anything, shouldn’t they communicate in an entirely new language and with totally unique accents?
Actually, the story behind the cars’ accents goes like this. Each car would speak in the accent of the last human who drove them. Mind you, this theory was confirmed in an interview by one of the film’s producers. We only hope that they meant the cars would steal their accents and not “absorb” them by eating the previous driver!