 FAKE: When Marty overhears the scene in the first film in which he  and his mother are talking in the car before the Enchantment Under  The Sea dance, there is some dialog that was not in the first film  (Lorraine says that when she has children she will let them do  whatever they like, and Marty comments that hed like to have that  in writing). The novelization of BTTF1 does contain this dialog,  suggesting that it was originally in the script and may even have  been filmed, but Marty says it only in the second and not the first  film.