In Chapter 4, when the Sheriff and gang arrive at the parking garage to examine a victim, a little boy claims he saw the whole thing: "The car pushed him out, then sped off, but I didn't see where it went."

Here's the thing: Back up a few minutes (in Chapter 3) to when the Sheriff, responding to his niece in trouble, speeds past the autobot in question and we can clearly see the license plate (6FOW433). Now, back in the parking garage, when Opie says he didn't see where the car went, look over his left shoulder and see a familiar license plate.