So if you're lucky, you might see a bit of broken plastic one day on your floor board and realize it's part of your pedal stop pads. If not, and you vacuum it up, then you're in for a frustrating experience. If one day you go out to your car, push in the clutch and it won't let you turn over the starter, this part may be the reason why. Over the years these wear out on the brake and clutch. For the clutch, it's used primarily with letting the car know you've disengaged so it can safely start. For the brake, it sends the signal to turn your brake lights on and off. For both of these reasons, these are good to have for those of us you like to hold on to their cars a long time and/or buy used cars.