When you open the glove box and let go, does it just thunk straight down or does it go down slowly & smoothly? If it thunks straight down, you need to reattach the little thing on the bottom right side of the glove box. This slows it down... it's like a pneumatic door closer type thing... can't think of the name of it for the life of me right now.
This might be the source of the rattle.
This might be the source of the rattle.