if you say it only happens on bumpy roads or over bumps.. sit inside your truck and try tapping on different things with your hand to se if it squeeks.. like the dash, over the radio, th glove box area, mine makes a noise when i go down my dirt road and its coming from like behind my radio.. just throwing ideas out there...

 

Are you sure it's not the upper dash part rubbing on the windshield?

My guess is that there is part of the dash rubbing on some random part. The only thing that I can suggest, is to tear apart your dash as much as possible and put napkins between everything that touches another or a dab of silicone. Behind the radio, there is nothing but plastic vents that route way through the dash. One of those is may be touching and rubbing another item. Your radio is easy enough to take out. I would take it out and drive through the neighborhood again and see if you can get closer to the noise.
Maybe even drive around one more time and see if the noise is echoing through one of the vents? That would mean a vent tube is rubbing.

 

Ill give it a shot.

 

Ill give it a shot.

 

My 2008 was doing the same type of thing. There was a real good tech at a dealer here. He rode with me, heard the noise. He got out and asked me to open the hood. He removed a couple of "rubber bumpers" that the hood rested against when closed. The noise is gone. If you open your hood and look at the bottom of where the hood is closet to the bumper of the truck and at the farthest area from the center. Remove them and I would be willing to bet the noise you are hearing will be gone.

 

ill go out and try that now

 

UPDATE: tried removing the hood bumpers - didnt work and tried the cup holders,dash and glove box - didnt help. ill figure it out some day,lol

 

Take the front door panels off its only about 2 minutes per side.

 

this may sound funny but my 07 was making that noise I could not figure it out for months then I found the problem I knew it came from the right side while I was driving. I found out that where the passenger sun shade touches the roof of my truck there is a outward indentation and when I pushed where the shade touches the roof IT MADE THE Noise I have located it but I am not sure how to stop it. hopefully this is helpful and is what's wrong with yours to.

 

My truck makes the same noise. I'm pretty sure it's pieces of plastic in the dash rubbing together. I'm tempted to take my dash apart and isolate anything that could be rubbing. I'm holding off though until I have the rest of the interior out to dynomat it. In the meantime I just turn the stereo up and I don't hear it anymore.