dash rattle

Are you sure it is inside the car? Many toyota's have similar rattles or clicks coming from the plastic trim covering the windshield wipers. It is loosely mounted and hits the bottom of the windshield especially in cold weather. If you look at other brand cars like my Chrysler 300M it is tightly screwed in place so it cannot move. But Toyota is using cheap push pins to hold it in which for long enuf to move the car off the lot. Some people use silicone sealant to glue it down.