On the back of the plastic lower door panel, there are eleven of what look like #8 x 3/4" wafer head phillips self piercing screws. The head diameter is about 9/16". They screw into nuts that are attached to the door panel. I have two problems: 1) I don't know what they are for. I assume they attach the door panel card (the flat piece with vinyl covering) to this lower door panel, but I'm just guessing. Does anyone know how to use these screws? 2) I'm missing 8 of these special screws and can't locate source anywhere on the internet. Anyone have any? Or a source? I've attached some pictures.