Fuses And Circuit Breaker problems of the 2006 Toyota Sequoia

2006 Toyota Sequoia has experienced intermittent electrical problems since purchase. On 30 July 09 vehicle experienced multiple computer failure of ecu, vsc, and other computers. Toyota tech reps say vehicle could not have caused problem, therefore it must be an "external' fault. However, there is absolutely no evidence of any external arcing or other power surge indicative of an "external" event. Toyota refuses to admit potential of a latent defect and says incident must be referred for insurance. Toyota will not address logical questions as to why other (non-protected systems such as the radio) in the vehicle still function in light of the alleged "external event. " additionally, there were no circuit breaker or fuses blown, so again how is it possible for the "external event" theory to be valid? given the anecdotal evidence on the web concerning Sequoia ecus and vsc computers, what action can NHTSA take to have the manufacturer address the problems?.