The folks at Cinema Sins have made a name for themselves by pointing out continuity, editing, and other errors (and some things that arguably are not errors) in popular movies (Titanic, The Dark Knight, Inception, et al). At their best the zippy videos strike a balance between nitpicky and epiphany-inducing.
Now they have tackled one of their "favorite movie[s] of all time," Back to the Future, and it's pretty fun. Why are there X-rated movies playing in the middle of town? How does Doc get into the Delorean, with its vertically opening doors, when it's in the back of his truck? How do the Libyans know he's at the mall? And so on and so forth and so on.