When Sidney gets off the bus from high school to her empty house. Two voices come from inside the bus saying goodbye to her. As the bus drives off it becomes very clear that there is no one in the bus. This was probably because it was cheaper to to get just a driver and they figured no one would notice.
I've seen many people writing this as a slipup, and I'm surprised. Because it's so obvious that a girl is stretching out, waving, from the fourth window from the right. Did you watch the widescreen-edition? I did, and there it's clear that the bus is not empty. And for the other voice, maybe sat next to the first girl so that you don't see her.
As a matter of fact, there is another girl in the bus besides the one that you see. If you put in the DVD version on widescreen on a large TV, where the picture is huge, you can see another girl in the bus.
on a lot of movie's where there's a bus you can't see inside it. and why does it have to be so specific that there HAS to be someone on the bus. all you need is a voice to get the idea that someone's on the bus
I have yet to see it in the modified version, but it is very obvious in the wide-screen version that there is a girl hanging out of the bus window waving goodbye to Sidney. You probably are watching the version "formatted to fit your screen". Check out the wide-screen version.