Continuity mistake: When Danny & Debbie are having their New Year's dinner at home, the champagne foam instantly disappears in the very next camera angle after pouring it.
Continuity mistake: When Terri is at the party, her blonde wig changes shape and size many times.
Continuity mistake: The Bird of Prey is the one captured by Kirk's crew in ST III. That ship's bridge showed Klingon Cmdr Kruge in his elevated command chair with his helmsmen arrayed circularly below him, and nothing else. ST IV has this same ship; however, the bridge now resembles The Enterprise layout with Kirk's command chair behind Sulu and Chekov at their rectangular helm, with Spock, Scotty, and Uhura at their usual positions.
Suggested correction: According to the captain's log at the beginning, they have been on Vulcan for 3 months. As they prepare to depart, we see several Vulcan technicians moving equipment in and around the ship. It's quite conceivable that the bridge was reconfigured according to the crew's specifications to facilitate their use of the ship. This may seem a bit excessive, as the remodel includes the door onto the bridge, and the frame of the door, and possibly most of the rest of the ship. But it's not outside the realm of possibility. The real mistake, though, is why they would go to the effort of installing new workstations on the Klingon bridge and marking them with Klingon labels, instead of standard Federation text. Interestingly, though, the "Starfleet" style bridge layout of the Klingon ship is being used by the Klingons on the Bird of Prey in Star Trek V.
Continuity mistake: When Johnny 5 nearly drives the snack wagon over the edge to where it is hanging, it appears to have miraculously moved right back from the edge, making it look like he never went nearly over in the first place.
Continuity mistake: The rear view mirror disappears when Jeanie is speeding home.
Continuity mistake: In one scene, Steve Martin is shot in the arm and bleeds, but when the trio return after the riot the wound has disappeared.
Continuity mistake: When Walter is watching the fire go through the electrical system in the walls of the kitchen, watch the blender. One shot shows thick, chunky, white/orange stuff flowing out over the edge of the counter. The very next shot shows the blender toppled, but very clean. There is no trace of the chunky stuff in the blender or on the counter.
Continuity mistake: There is a scene where Molly Ringwald is confronting her father about lying about seeing a counsellor. His hair is sweaty and messed up a bit and then it changes position to Molly Ringwald and back to her father. Then you will notice that his hair is combed.
Continuity mistake: At the Policeperson's Dance, Copeland spills punch over the Commissioner's wife's white dress. As the camera view switches, her dress is already stained before she is splashed.
Continuity mistake: At the least swim meet, Chaz is shown diving before Jason Melon. Howver, after Jason dives, it then shows Chaz "up next" - and his hair is completely dry.
Continuity mistake: When Seymour tries to kill the plant he pulls a gun, the gun is a six shooter, the plant grabs the gun and fires at the guy, then he fires some more, in total the plant fires 9 shots with a six shooter...
Continuity mistake: When the heroes dedicate their boat, Demi Moore's character knocks a hole in the side of the boat. In subsequent shots, the hole looks like it's been partially repaired.
Continuity mistake: At the end where Jackie jumps from the side of the cliff to jump onto the hot-air ballon he starts off only a couple of hundred feet from the ground. Then in the next scene he is a couple of thousand feet up, like he has just jumped from an aeroplane.
Continuity mistake: Early in the movie, we see "Woody" driving a 1969 or 1970 Red Mustang. At the end of the movie, when he is driving his friends over to the mayor's house, he is driving a much older Mustang, either a 1965 or 1966. It is red like the first one, but the car's body style is obviously very different.
Continuity mistake: When Jack Burton and the rest of the gang escape from the Wing Kong Trade Centre the first time, the guards fire at the left side of the bus breaking the windows and making holes in the bodywork. When we see the bus a few seconds later as it is driving away, it appears undamaged.
Continuity mistake: When the old man is talking to Chandler on the porch in Tibet, he picks his nose with his pinky finger. When it cuts back to him, he's picking with his index finger instead. (01:04:30)
Continuity mistake: When Highway first assembles his men, it is meant to be very early morning (5:00 am.). Judging by the very short lengths of the shadows, it is quite obvious that it is around noon.
Continuity mistake: Watch Gwenda's headrest after she leaves the station in her car. It disappears between shots.
Continuity mistake: At the end of the movie, Spence is seen with Claudia in a western movie. He walks through the swinging bar doors with a cigar in his mouth. He takes a few steps forward and the size of the cigar has nearly doubled.
Continuity mistake: During their escape the three protagonists have to wade through a canal. A few moments later their clothes are dry again. (01:02:15)