Yesterday, I hauled a load of dirt. After I was all done, I washed the truck but ever since then, I've notice dirt on my rear bumper. I thought it was strange that I would miss that during the wash so I went ahead and clean it again. After this happened a couple of time, I started to investigate. It appears that I've got dirt inside the tail gate. Every time I close the tailgate, bits drop out the bottom. I guess it will eventually all come out but it's a little annoying. If I open and close the tailgate quickly, I can hear it rattling around. Any ideas?