Audio problem: In the beginning of the movie when Clark is preparing to light the Bar-B-Q, He squirts charcoal fluid out of a plastic bottle. Then Ellen squirts more fluid onto the coals out of the same plastic bottle. Listen to the sound; it is the distinctive sound of a metal charcoal lighter fluid bottle. (00:07:45)
Revealing mistake: During the scene when Audrey is having a nightmare about eating too much while on vacation, the nightmare ends with her inflating like a balloon from all the food. Her blouse splits open and down the middle, where the buttons have broken, the dark balloon used for the effect is visible. (00:16:35)
Continuity mistake: When the Griswalds are leaving the hotel in London they get in the hire car. When Clarke realises that the steering wheel is on the other side he gets out. When Ellen gets out she leaves her door open but when Clarke goes to get in the door is closed. (00:24:20)
Continuity mistake: When Clark first hits the bike rider with his car, he is nursing his left leg, but later, at the hotel in Rome, he has a cast on his right leg. (00:26:50)
Visible crew/equipment: When the Griswolds are in Italy, Ellen sees the billboard advertising her seductive video. She storms away and is later seen backing up into a parking spot at their hotel. The driver is a huge stunt man and notably much larger than Ellen (if not most women) and when parked the petite Ellen exits the vehicle. (01:18:05)
Audio problem: When Clark is chasing the kidnapper, his car has a blowout. Even in the theatrical version, you hear him say "Darn it all," when it's clear that he's mouthing the F-word, along with something else. (01:26:30)
Continuity mistake: Near the end of the film as the Griswolds flight back to the U.S. approaches New York City, Clark points out that the Statue of Liberty is visible below. The Griswolds are all seated facing forward (in the direction of flight) on the left side of the aircraft, and are looking down on Lady Liberty through windows on the left side. When we see the subsequent shot of the statue passing by below, the point of view is from the windows on the right side of the aircraft. (01:30:05)
Continuity mistake: In the Italy scene after the visit to the Traveler's Cheque center, the Griswold's decide to go shopping with the $3000 they received. Rusty proclaims "Yeah Dad, we've been in these clothes a long time, I feel rank." Shortly after walking out of the store wearing their new clothes it changes to the scene right before they see Ellen on the billboard, and they are back in their old rank clothes.
Continuity mistake: When Ellen is dancing for Clark, she slides down against the door. There is pink toilet paper by her feet which disappears.
Other mistake: After the Griswolds leave the German couple's house, the man says "Who the hell were they?", and the woman says "Beats the shit out of me." However, since they slept there overnight, they had enough time to discuss it in private much earlier.
Continuity mistake: This is the only movie in the Vacation series where the Griswold name is spelled "Griswald." This is shown on the beginning credits on Clark's passport as well as family name on Pig in Poke game show.
Factual error: The supercharged "Honda 750" motorcycle is actually a Honda Rebel 250.
Audio problem: When the camera thief tells the Griswolds to take their shoes off and get in the fountain, Ellen is heard reacting to the cold water, but she hasn't even gotten in yet.
Audio problem: When the family is atop the Eiffel Tower and Rusty is flirting with a woman, a dog barks but it doesn't make a bark motion. When we see it bark a second time it actually is barking.
Audio problem: After the Griswolds first arrive at the Oktoberfest, there is a wide shot of them walking in with the crowd with the band directly behind them. The drummer is hitting the cymbals but the sound isn't matching.
Answer: They're a lynch mob. Remember what Rusty's date said: Girl: They haven't rang those bells in years! Rusty: What do they mean? Girl: They're going to hang someone! (pause) Rusty: Dad.
Brian Katcher