While driving at approximately 60 mph with no car within 200 yards in front of vehicle, no object on the road, and no collision was imminent, the vehicle suddenly and spontaneously slowed down to almost 5 mph from about 60 mph for no reason. The seat belts pretensioned, the gas pedal dropped out from driver's feet. City safety activated. All occupants developed mild whiplash. It took several second to get car to return to highway speeds. Dealer claims it was due to a toll tag that was placed to closely to the city safety system near the rear view mirror....updated 12/03/15

- Frisco, TX, USA