sometimes the metal latch where the hatch snaps into place will rattle. you can wrap it in electric tape. there's also latches for where your back seats snap into place, you could check those. sometimes the sunroof will have a rattle too. If it isn't any of these, and you're sure it's right around the driver seat, it could be something under the seat or may be something to do with the seat belt. beyond that, i got nothing