I am very confident the rattle is caused by the cover hitting some other parts. The rattle disappears when I drive without the cover. Also, when the cover is intact, I notice if pressure is applied to the left on the inside of the glove box, the rattle disappears as well.
The weird thing is if I removed and reattach the cover, the rattle may disappear for a few days. However the rattle return immediately if I attempt to secure the cover by shaking and applying pressure. <_<
So Lexus will replace the cover upon my request?