Where Do They Start? Marty McFly hits 88mph in Doc Browns customised DeLorean in 1985.Where Do They End Up? and drives into 1955.Biggest Culture Clash. Can I get a Pepsi Free? asks Marty, sparking shop owner Lou to insist, You wanna Pepsi, pal, you gotta pay for it.Unresolved Paradox. The biggie. if Marty has such an impact on his future parents lives, how come they dont twig theyre bringing up a son who looks just like Calvin Klein.