Continuity mistake: Eddie (Quaid) takes Clark (Chase) to the casino buffet for dinner. As they fill their dish with food, Clark tells the server behind the buffet table that the chicken and beef dishes are labelled incorrectly. The server then switches the tags, placing them in each dish. In the next scene he repeats the switch.
Continuity mistake: When Clark first meets Marty at the Blackjack table, he is dealt a hand. If you look closely at the cards, they change suit and number from when they are dealt to when the hand is over.
Continuity mistake: Right when the guy dies at the end he's leaning straight up against the chair, but the next shot of him, he is leaning to the left.
Continuity mistake: In addition to the submission regarding the tour van acquiring damage to the hood after crashing through Wayne Newton's house, the mirror on the drivers side is bent. In the next shot when Clark exit's the vehicle and closes the door, the mirror is gone.
Continuity mistake: At Hoover Dam, Clark pulls out a small rock and causes a little leak. While he's fixing, it another develops. He puts his left side against the second leak to hold it until he gets the gum in the hole. The water stain on his shirt changes from his left side to his right side, then eventually his entire shirt, in different shots.
Continuity mistake: In continuity of Rusty's fake ID lacking the Vegas background, both his right and left hand are covering significant parts of the text in the oversized ID he is holding which doesn't appear in the copy of the ID.
Continuity mistake: When Clark is getting breakfast and he is reading Card Counting, at first, you see him holding the book by the sides, then you see he is holding it by the bottom middle, then the sides again.
Continuity mistake: When Russ takes his fake ID picture on the street, and he sticks his head in the giant license and there is no backdrop behind his head...you see Vegas light behind him.. but when the casino guy checks the fake ID, it is all white behind his head... no Vegas lights.
Continuity mistake: When the family sits down at the table and the camera pans back and forth from Audrey and Rusty to Ellen and Clark Audrey's hair is in front then it's in back and it changes about nine different times.
Continuity mistake: When they are at the Wayne Newton concert, and Wayne starts walking towards Ellen, when you see a back shot of Clark and Ellen, you see Clark looking towards Ellen, but in the next front shot of them, he is looking straight.
Continuity mistake: When the guy says "take the ticket at the end" and then drops it, the ticket changes in all of the shots that you see it.
Continuity mistake: When the mom is with Wayne she gets covered with pasta. In the next sequence she is running down the hall with Chevy Chase looking for Rusty where she still has noodles over her right shoulder. as soon as she steps into the room the noodles have disappeared.
Continuity mistake: In the Hoover Dam scene, the tour group is walking through an underground tunnel when Clark messes with the wall and more water than normal starts coming out. He gets gum from Audrey and starts plugging the holes. He puts gum on the first hole and when the gum makes a bubble filling with water, he puts another chewed piece on the bubble. In the next shot, there is no piece on the bubble and he puts a chewed piece on another hole in the wall.
Continuity mistake: At Cousin Eddie's "house", right before they go to Hoover Dam, in one scene a noticeable dust storm is happening but in the very next shot, its not.
Continuity mistake: When Sid Ceaser is fake-dying near the end, his head rolls backwards. In the next shot his head is on his right shoulder.
Continuity mistake: When Clark and Ellen are on the plane and go to the restroom to join the mile high club. Ellen goes to the back of the plane while Clark goes to the front.
Continuity mistake: When the family is on the airplane on their way to Las Vegas, Mrs. Griswold has her purse strap over her shoulder. In the next shot there is no strap. Later on when she is going to stand up, she takes the purse which is lying next to her and not over her shoulder.
Answer: The sign said $30,000.