I'm guessing that if you are about to be car-jacked you hit the button to blind and incupacitate yourself rendering you helpless. Then the assailant knows you are no danger to him and sort of pities you. He rolls you out of your car knowing you have suffered enough without shooting or stabbing you.
They probably mean side-view "wing" mirrors though.
Whatever happened to CN teargas? That’s what they should use. I was required to take a whiff of it. Bad stuff that will disable anybody stupid enough to hang around.