What if the Back to the Future franchise continued?

Trilogies and trilogies plus are all the rage nowadays. The fact of the matter is it's hard to have a trilogy wrap up, and everyone is satisfied. Back to the Future is one of those that got everything right.

Once the trilogy ended, sure, people had their "favorite" movie of the series, but as a whole, everyone seemed satisfied.

What if it would have kept going? If everyone involved was happy with a script, and they made the movie...what would it look like?

Well, some clever fans went ahead and made a trailer for Back to the Future IV.