I've only had my 04 Portflio a few weeks and pretty much have the PO's oversights taken care of except... it sounds like a lug nut is rolling around inside the dash! Emptied out the glovebox which made no difference of course. The sound is coming from the center anyway, not the glovebox. Pulled the center trim off and see the nav unit and blank plastic. Do I really need to start disassembling the dash now?

 

Well about 75 reads now and no suggestions, so I guess the silence is your answer. Keep looking.

 

I have the same issue on an old Ford Cougar I am restoring, there is no fix until you get a definite location, if your lucky you grab it, if your not you can use expanding foam to stop it rolling about. If all else fails then volume 14 on the radio might help a bit !!

 

Mine had a rattle that turned out to be the left side defroster vent. Stuffed a piece of felt between the vent and the windscreen and fixed it. It sounded like it was inside the dash.

 

Just kinda hoping for an "aha" from someone. Looking at the JITC makes me leery of dash surgery.

 

Try removing a panel at a time. The top center panel (with A/C vents) comes off easily. Then move to the instrument panel, next take out the center console and start on the bits around and above the radio.

There are threads on how to do this, as well as Rev. Sam YouTube videos on most.