Trivia: When Kevin is in Buzz's bedroom, he finds in the box a picture of Buzz's girlfriend. This is actually a picture of the art director's son dressed up to look like a girl, because the director, Chris Columbus, thought it would be too harsh to make fun of a girl like that.
Continuity mistake: When Kevin goes outside the first time and sees the cars in the garage, the light isn't on. When it shows the garage again in the next shot, the light is on. (00:20:25)
Suggested correction: The light could be motion activated. Either Kevin's movement or passing vehicles could have turned it on, regardless of the time of day. I have motion detector lights in my carport and they constantly go on and off in the daytime if it's low-light and cars pass by fast enough. People walking their dogs can also activate it if they are close enough. They sometimes stay on until I have to manually turn the power off, then on again.
That would explain it only if the light came on when Kevin "activated" it. It stays off during the first scene, and he doesn't make any motion towards the garage when the camera is on him. Nor do we see any vehicles or people pass behind him.
How likely is it that this movie - taken in 1990 - had access to the developed technology that we have today, to make automatic lights turn on?
Infrared motion sensors were around in the 80s.
Continuity mistake: In the shot where Buzz is eating the slice of pizza, he is shoving it into his mouth all bent up. In the next shot from another angle, he is eating it flat and it seems to be a whole new slice. (00:08:50)