You know, it's funny, but my entire interior passenger side vibrates and rattles now. It all just seems to have started out of the blue last week. I thought much of it was the latch from the hanging seatbelt at first, but that is only a small % of it. It seems to come from the seat, the inside of the door, and somewhere near the back seat. Driving to work this morning nearly sent me postal! I guess it's time to settle down for a weekend and tear out the interior to find the culprits.