I have a 83 El Camino and have a kind of a squeek noise that comes from the drivers side of the dash. It happens when I hit bumps in the road. Other than that, That is about the only way I can describe it. Any good guess's are welcome.

There is about four 3/8ths or metric equivelant bolt that are used to keep the dash secure. Maybe the one on the passenger side is loose. Or it could be the glove box door.

That is my guess. I think it will be something that you might have to mess with a while before you end up locating the exact place.

Maybe you could have someone ride along or drive you and you look around and move things to see if you can locate the place. It could also be outside of the cab.

I had to take my dash apart to find one squeek. It was two nuts that hold the dash panel to the car.