Protocols
Compared to some of the plot-fails, this is small beer - but when the lady with child rings the police that someone is stuck in the trunk of the car in front, surely protocol is to immediately say to her "From this moment... please do not bring attention to yourself! No papping your horn, no overtaking..." etc.
But no - they wait until she's taking selfie's with the serial killer before they bluster and ask her to desist.
Halle Berry's: Ring back someone playing hide and seek with a serial killer was bad enough but no-one else seems that clue-d up either!