We were at a stop light and we were rear ended by a Lexus SUV. We're assuming she was going 45mph + but we're not too sure yet. I couldn't figure out why myself, the drive of the car that was hit, had such a horrendous neck ache after being hit. I turned around & saw that my headrest had been completely ripped out of the seat itself, providing no support for my head and/or neck on impact. I can't find any information of if this is on purpose, as a safety feature, or if the headrest failed.