ABC News -- Federal safety officials said today that the underlying cause of the some 2,000 so called runaway Toyotas remains under active investigation. Until today, Toyota had solely blamed either the wrong floor mats or driver error. The government's statement comes as a growing number of Toyota owners are coming forward to insist that floor mats don't explain the mystery of what happened to them. What should you do if your car accelerates out of control? A "Consumer Reports" engineer explains in the video below. To see all of ABC's Brian Ross' reporting on accelerating Toyotas, CLICK HERE .