Other models are at risk for jammed floor mats. Owners of Toyota and Lexus models beyond the seven models covered by the recall have complained of jams and runaway vehicles, says Sean Kane of Safety Research & Strategies.

"If Toyota says they are having an unintended acceleration issue, why are (those other vehicles) not being recalled, as well?" he asks.

Floor mats are not the only issue, so more models should get smart pedals. Clarence Ditlow, executive director of the Center for Auto Safety, says Toyota has had unintended acceleration complaints including in models where floor mats are not an issue for a decade now, starting with a Lexus model in Great Britain.

"We do not believe this is just a floor-mat problem," he says, and says Toyota should expand the range of vehicles getting the smart pedal to include all with electronic throttle linkages.

Given how the problem has dragged on, lax enforcement by an underfunded NHTSA may also be an issue, says Sid Shapiro, a Wake Forest University regulatory law expert. Toyota, he adds, could try to be more "transparent" about the troubles.