DRIVING DOWN RURAL ROAD AT APPROX. 40MPH, SUDDENLY FELT SNAP TO BACK OF HEAD. FORCE WAS SUCH THAT DRIVER THOUGHT PERHAPS SHE HAD BEEN REAR-ENDED. PULLED OVER TO SIDE OF ROAD. NOTED DRIVER SIDE HEAD REST HAD SPLIT/SEPARATED WITH LARGE V SHAPED SEPARATION IN HEAD REST.*DT CONSUMER STATED SHE HAD A STRAINED NECK AND CONCUSSION.*JB