Have you got a passenger side dash rattle? Possible fix...
 

I had, and despite three 'no fault found' attempts (using word loosely) by OPC, it remained.

However, have fixed it myself.

It was a 'plasticky' rattle that was driving me mad - over every bump and undulation.

Turns out it was the plastic elbow between the A/C ducting behind dash and the passenger dash air vent assembly.

I removed the 'end plate' off of the dash and could see the elbow, and also see that it was loose from its connection to the A/C ducting. Hence the plastic sound rattle.

You could just push it back on (but it would simply come loose again). I wedged a bit of pipe insulation between it and the end of the dash to stop it moving.

Job done. Sanity restored.

Great post, thanks. I've had this issue off and on - kept looking in glove compartment, etc.

thank you! i wonder if there is a fix for the gauge cluster rattle as well (other then pushing i further in).

I will try this this weekend. Been driving around with cupholders out and passenger seat buttons taped up. Can't tell where that damn rattle is coming from but sounds exactly like where you indicate. Problem for me is, gf says she thinks it's coming from either under the seat or behind her. I wear hearing aids so I defer to almost anyone else for things sound-related. Thanks for the tip.