Oh crap...did she hit someone? She didn't see anyone, but it sounded like she hit someone! Her question was answered in a way that didn't lower her panic levels any when a costumed face appeared at her window. Her first impulse was to punch through the glass and try to knock her hitchhiker off, but then the masked woman just asked her to pull over, and...politely, at that, of all things. It served as a reminder that she wasn't in kill-or-be-killed Gothic anyone, at least. Besides, punching would involve her releasing her white-knuckle grasp on the steering wheel, and that clearly wasn't going to happen.
Instead, she half-turned her head, eyes that felt like the must be the size of saucers trying to look at both her unexpected passenger and the road/sidewalk ahead. "HOW?!"