Uncle Buck (1989)

Continuity mistake: When Buck is on the highway driving to the house and trying to remember the kids' names, we see a white 4x4 travelling the same speed as him but several lanes over. When it cuts to a shot of the rear of Buck's car, there is a small sedan now in the left lane beside him that wasn't there before.

Miles: Where do you live?
Buck: In the city.
Miles: You have a house?
Buck: Apartment.
Miles: Own or rent?
Buck: Rent.
Miles: What do you do for a living?
Buck: Lots of things.
Miles: Where's your office?
Buck: I don't have one.
Miles: How come?
Buck: I don't need one.
Miles: Where's your wife?
Buck: Don't have one.
Miles: How come?
Buck: It's a long story.
Miles: You have kids?
Buck: No I don't.
Miles: How come?
Buck: It's an even longer story.
Miles: Are you my Dad's brother?
Buck: What's your record for consecutive questions asked?
Miles: 38.
Buck: I'm your Dad's brother all right.
Miles: You have much more hair in your nose than my Dad.
Buck: How nice of you to notice.
Miles: I'm a kid - that's my job.

Trivia: In the scene in Maizy's class near the beginning of the film, the little girl with long blonde hair sitting at the desk next to Maizy is a young Anna Chlumsky, who went on to be the star of 'My Girl' and 'My Girl 2'.

Question: In the scene where Buck's brother rings him up to babysit there is a body in Buck's bed. In the scene before Buck is at a bar but brings no one home from the bar, so where did the the extra person come from?