It's surprising how many "Easter Eggs" and such are found in that movie. There are several videos on youtube that document them. I watched one a couple of weeks ago and was surprised at how many I never noticed, despite having watched the entire trilogy more times than I want to admit. For example, the mailbox smashed when Marty goes back in time has the name "Peabody" on it. When the farmer, Peabody, and his family come out to investigate all the noise, the son (with the comic book) is called "Sherman". An obvious reference to Mr. Peabody and Sherman of cartoon time traveling fame (via the WABAC machine), yet I never picked up on it.