Continuity mistake: When Gonzo is flying in the air holding on the balloons and then is shot down by Doc Hooper and lands on the car, the last two balloons are yellow and pink, but when the car takes off after Gonzo lands on the roof - the two balloons are now both blue.
Continuity mistake: Kermit's ice cream in the fair scene changes colour.
Continuity mistake: In the scene where Kermit, Fozzie, and the gang are following Gonzo, who is floating from the helium balloons, Fozzie opens his door and looks up at Gonzo. When he comes back into the car after Kermit shouts at him to do so, the steering wheel comes loose from the dash and all the Muppets start yelling at him for being reckless. In the next shot of the interior, the steering wheel is back in place. I do feel maybe this was a blunder that was left in on purpose, because it was so funny the way all the puppeteers ad-libbed a reaction to what shouldn't have happened, but it fails in continuity because in the next shot the wheel is fine.
Continuity mistake: When Kermit and Fozzie come round the corner and see the billboard with Kermit's face on it, you can see that there is nothing behind the billboard. Yet later when Doc Hopper and Max are leaving, Hopper's car is behind the billboard. The car slightly sticks out, so Kermit and Fozzie should have seen it.
Continuity mistake: In the outer office, as the secretary begins to sneeze, the fan is already on. Kermit then goes to turn on the fan to blew animal dander at her. Also, as they make noise, Kermit is heard talking, but his mouth doesn't move.
Continuity mistake: As Kermit faces Hopper, there's a large black square behind Kermit, between Fozzie and Doctor Teeth that only appears in the long shot.
Continuity mistake: When the duo stop at the church, the wording on the sign is either shaded or dingy. But a moment later when they go to get out of the car, the sign's lettering is clean and bright.
Continuity mistake: In the close ups of Kermit playing the banjo, his arm moves, and when in wide shot, only his hand moves over the strings.
Continuity mistake: As Hopper asks Kermit about being rich and famous, he goes to stroke the back of Kermit's head. As the angle changes, Hopper's hand is under Kermit's chin.
Continuity mistake: When Kermit and Fozzie meet Big Bird, their car stops about fifteen feet behind him, at the end of some dark tire tracks. But when the camera looks at the pair in the car, they're looking directly at their left, and Big Bird converses with them looking to his left in quarter profile to them. When they leave, their position is about ten feet back from the end of the marks, a good twenty feet from where they originally stopped.
Continuity mistake: After Kermit is tossed over the crowd in the El Sleazo, he catches on a ceiling fan, and it swings a bit from the impact. After a shot of the bartender speeding up the fan, it is no longer swinging. This is impossible with any weight on one blade. When Kermit is slung off the fan, you can see the fan is not on at all, Kermit is at the piano, and just about everybody in the place is still looking at the fan.
Continuity mistake: The crack in Fozzie's Studebaker windshield comes and goes throughout the film.
Continuity mistake: As Kermit and Fozzie stop at the Frog Legs billboard, it's easy to see that it's out in the wide open. but when the "Myth, Myth" gag is used, there's suddenly trees directly behind it, where the lady pops out saying "Yes?"
Answer: This is Big Bird's only movie where he says this line. It is a reference to his going to New York hoping to get a role on Public Television (the station that created "Sesame Street") This is verified in TV interviews with the late Jim Henson and on Wikipedia.
OneHappyHusky