What would happen?

I wonder what would happen if someone had their head in a window on a car and then the window started closing. I only wonder this because I was watching a cartoon where that happened and it made me curious as to what would happen. I wonder if it would cut a person's head off. It seems like the glass would need to be a lot sharper if it were ever to cut through skin and bone. It might break the motor in the window. That seems unlikely too. This is what has me baffled. I can't see either of the options working, and I can't seem to think of an alternate solution.