The FANTASTIC FOUR reboot will always go down in movie history as a movie that could have been better than it's final cut but it was changed a lot during filming and post-production. In fact, the robot HERBIE originally had a part in the film until he was cut out during rewrites. (Missed opportunity on the highly popular little buddy robot trope used in film right now.)
Concept artist Fausto Dr Martini worked on the early development stages of the film and has shared his work on what HERBIE and the Fantasticar could have looked like.