On the 47-8 cars, their use is limited. If memory serves, they're used on the inner fenders to secure the removeable inspection cover (right lower inner fender). As the cars get newer, their use increased to being used to connect most of the inner fender parts to one another as well as other applications throughout the car. Until the fund reproduced them, they were hard to find and as I parted out cars, I would hoard them.
