As The Times' Ken Bensinger and Ralph Vartabedian have reported, Weiss says he had stopped his 2008 Tacoma pickup at an intersection in Long Beach in October when the truck, on its own, suddenly accelerated toward oncoming traffic. He was able to avoid a collision by clamping on the brakes and turning off the engine, but the incident left him reluctant to get behind the Tacoma's wheel again. And Weiss says the mats weren't the problem -- he'd removed them months ago on his dealer's advice. His experience, combined with similar complaints by other Toyota owners and additional pieces of evidence, points to a potential electronic problem, not a mechanical one.

Weiss was fortunate that his truck didn't have a keyless ignition system like those in many Lexus and Prius models. To turn off one of those engines while moving, drivers must press the "on" button for three seconds -- a task that's neither intuitive nor easy in a runaway vehicle.

Toyota insists that there are no problems with its "drive by wire" electronic throttles, a standard feature in all of its current cars and trucks. The technology's supplier tested it for sudden acceleration problems three years ago at the request of the National Highway Traffic Safety Administration, and it received a clean bill of health. In response to a complaint this year, the NHTSA again blamed the floor mats.