I don't know if this image matches the cars that have recently been in the news as having uncontrolled acceleration issues, but take a look at that gas pedal shape and placement. Notice that it's a long lever and we're pretty far from the fulcrum (which is possibly far inside the engine compartment) -- any return spring attached further up, to return the pedal to a closed position when it is released, is going to have to work hard. That floormat looks fairly heavy, and may have "grabby hooks" on its undersurface that would make it impossible to move very far all at once, but it might slowly creep forward under use, with a sort of ratcheting effect. Then notice also that you might have to push the pedal down farther than usual -- meaning you may already be accelerating going at a high speed before the problem has an opportunity to occur.
