National Lampoon's Christmas Vacation (1989) - 14 major mistakes

Revealing: At one point when Clark is flying down the hill through snow drifts on his saucer sled after greasing it up you can see the guide wire pulling the sled.

Continuity: In an early shot of the outside of the house, the motorhome that Eddie and family show up in is parked in the driveway. The problem is, they don't appear until much later in the film.

Continuity: When the Griswold's are driving to the tree farm, they are being harassed by the rednecks in the truck.  Several shots of the front of the truck show only two passengers, but one view of the truck through its rear window shows three passengers.

Continuity: After Eddie et al arrive at the Griswolds, "Snots" is introduced. When everyone else has gone into the house, Clark is left outside with the dog. A shot shows the dog at Clark's side, and if you look at Clark's sleeve, he's wearing a sweater, but actually has on a windbreaker. At the end of the movie, Clark's wearing the sweater. Apparently the shot was taken of him and the dog, and edited back into the film early on.

Continuity: When Clark Griswold is on a ladder putting Christmas lights up on his house the trees in the background are green and leafy, (not evergreen trees), indicating summertime, although there is snow on the ground and it is supposedly winter.

Visible crew/equipment: Just before Clark goes down the hill on the saucer sled you see the view down the hill. If you look carefully at the right of the screen you can see two pinkish cables stretch into the distance. These are the pyrotechnics that make the explosions when Clark sets off. You can see it clearly on the DVD version, but not too clearly in the VHS one.

Continuity: In the opening scene, when the family is on their way to get a Christmas tree, they get into a road rage battle. If you look closely at the shape of the headlights, the car the family is in and the stunt car are noticeably different.

Other: When the Santa Sleigh is launched in the air by the ignited sewage, the sleigh flies over the moon. Now on the DVD version of the film, it's not clearly visible, but on the VHS version, you can clearly see there's a box around the sleigh that looks like the sleigh is under a microscope slide.

Continuity: When Uncle Louis drops the match in front of where Eddie empties the "chemical toilet" if you look VERY close you can see the rope that launches him into the air.

Visible crew/equipment: When Clark gets his "Christmas bonus" he starts going off about what a lousy guy his boss is. During his outburst you can see a crew member's head pass by the bottom left corner of the screen

Continuity: When Uncle Lewis and Aunt Bethany arrive, the wreath on the front door is lit with Christmas lights. When the door opens from inside the home, there are no lights on the wreath....it is just plain green.

Other: After Eddie kidnaps Clark's boss, he drives off and if you look at the ground the snow looks like soap bubbles, because you see them waving around.

Visible crew/equipment: I've noticed in a couple of scenes where Chevy Chase and Beverly D'angelo are standing in the front hallway of their house: you can see the wooden rafters of the ceiling of the set in the dining room.

Continuity: When Clark is sliding down the hill on the sled, several times you can see fins on the bottom of the sled to help whoever was riding the sled control the direction a little better. When Clark is rubbing the oil on the bottom of the sled before he starts the sled is completely flat on the bottom.