I love this stuff. I’m surprised it took this long for someone to do this. Here is a video comparing the end of Back to the Future with the beginning of Back to the Future II. Most people probably don’t realize that the actress playing Marty’s girlfriend was replaced with Elizabeth Shue. So to make the second movie work, and to show the end scene from the first at the beginning of the second, it had to be re-shot.
Via I Watch Stuff