I'm finding the rear outboard seatbelt latch(es) (the silver part) rattle against the hard plastic (where they rest against the forward interior wheel well) when not in use. When the vehicle was delivered to me, the latches were secured BELOW the plastic clip that holds the seatbelt in place when not in use.
For now I try to ensure they're secured either ABOVE the small plastic clip that holds the seatbelt in place or I try to tuck the latch BEHIND the clip so it doesn't rattle. It seems to work well but it's annoying to hear the rattling when I forget to place the latches correctly. Consequently, I may have to do a DIY project with some "felt" glued onto the plastic outboard sections.