Just this past week, I've been noticing a VERY annoyin rattle which sounds like is coming from the passenger dash area. It literally sounds like something is bopping around in the glove compartment, although I've completely cleaned it out in attempt to pinpoint the problem. It only sounds when going over bumps, which is rather frequent in the area.

Again, it's just sounds like a piece of plastic bopping around in the dash; however, it is possible it's coming from the passenger-side door. Any suggestions or ideas before I start tearin things apart? Thanks!