The NHTSA investigation is the best way Tesla has to insure the safety of the Model S and restore consumer confidence. Unlike the Chevrolet Volt, the Tesla fires occurred on the road and not in the lab. Unlike the Volt, the Tesla had three fires not one. Tesla needs to fully cooperate with NHTSA to determine the problem is lack of a shield and not a more serious battery problem like the Boeing Dreamliner.
Under United States v. GM, a fire alone in a vehicle on the road without a burn injury to an occupant is a safety defect under the Safety Act. In one of the largest recalls ever for fires caused by a defective cruise control switch, Ford had a fire incidence rate of 65 fires in 3,723,142 vehicles or 0.001746% – no deaths, no injuries. The incidence rate in the Tesla is 2 out 19,000 (excluding the one in Mexico) or 0.011% which means the incidence rate is already 6.3 times higher in the Tesla than in the recalled Fords. The Ford recall was on 1995-02 vehicles (3-10 years old) so that exposure in terms of registered vehicle years or vehicle miles traveled is far greater than the 2013 Tesla which is 1 year old. Adjusting for exposure, the incidence rate on the Tesla Model S based on registered vehicle years is over 50 times higher than the recalled Fords in the cruise control switch investigation.