Did you know they actually re-shot the ending of BTTF1 for the beginning of BTTF2?
Michael J. Fox aged noticeably between the two movies and they completely replaced the actor playing Marty’s girlfriend. Hard to imagine i hardly even noticed (only in those moments where you go “look, he’ll emtpy the can into Mr. Fusion and THEN throw it in, too!” LOL followed by awkward silence cause it just does not happen in part 2 ).
20+ years later someone finally made a comparison:
Trivia aside, here’s a much better alternate ending: