I've noticed a rattle that has started to develop when going over severe bumps. It appears to come from the back/rear area. It is not the latch to fold the rear seats down as I have already put foam in place (learned that one early). Just checking to see if anyone else has any ideas of places to check. It's hard since I am usually driving so I can't go in the back seat and check. It definitely sounds metallic and it definitely sounds internal, not external.