And then the car wouldn't have saved then from being eaten by Aragog later - so we wouldn't have needed the next five books/movies.
Movie or real life - Titanic. Maybe don't go top-speed through the waters where the ice bergs are. If you do have to, maybe put enough lifeboats on board. If you're captain of the California, don't ignore the distress rockets. With those last two, maybe the movie would still be long; it would just be more upbeat.