How solvable are dash rattles

[Badbird2000]

I have a 2012 Silverado crew cab. Recently, I have noticed a rattle coming from the passenger side of the truck. It almost sounds like it could be in the dash, or even under the floor board. Sounds like a screw head has popped off, and is rolling around upon acceleration. I have tried turning the a/c off to see if that was a source, still there. I have checked the heat shield under the truck, as that is right where the exhaust is. Everything seems tight. I took everything out of both glove boxes, pulled the top one out altogether, still there. I completely understand the frustration techs feel when customers complain about rattles, etc. I just wonder if this is something a tech could track down. I have not been to the dealer yet. I may ask when I drop off for the next oil change.