The scene where Harry and Sally are driving to New York-- Harry is eating grapes and decides to roll down the window after he spits the seeds at the unopened window. So the window was supposed to be down--then there is a wide shot of the car driving--I think on a bridge--where the window is up again. The next shot returns to the inside of the car where Harry is still eating grapes.
Contributed by: Charles A
At the beginning of the movie, Harry and Sally are supposed to be heading to New York from the University of Chicago. The movie shows them driving along Lake Shore Drive with Lake Michigan on their left heading towards the John Hancock building. The problem is that the University of Chicago is on the south side of Chicago and the John Hancock building is on the north side. Thus, if you really were heading to New York from the University of Chicago (by way of Interstate 94), you would not be driving the route they took.
The next morning when both Harry and Sally call their friends to tell them about the sex the night before, you see a mirror on the wall behind Harry.
Camera people and staff are seen constantly walking back and forth; their reflections are highly visible in the mirror!