While driving home all of a sudden there was a loud pop and instantly hit in the back of the head WHILE driving. Instant headache and throbbing to the back of my skull. I pulled over as soon as I could to see that my driver side headrest had deployed. Further inspection it appears the plastic inside the head rest is broken so it can not be reset. This is an extreme safety issue! Just driving down the same road we've driven on multiple times to be hit in the back of the head while driving. If my wife was driving I am not sure how that would have turned out as she already has neck issues. THE CONSUMER STATED THE VEHICLE HAD NOT BEEN REPAIRED AS THE COST IS TOO HIGH. THE CONSUMER STILL DRIVES THE VEHICLE.