I might be wrong but I tend more to 1975-76 Dodge Monaco. Look at the front grille, it's not split like in '77. The police car at the end of the movie IS a 1977-78 !
corolere you're thinking about a Monaco which is a B body and has a split grill in '77 and '78. This is a Royal Monaco, a C body and I'm pretty sure it is a '77.