My '07 Tahoe has a rattle sound and I have no idea what it is. I have taken it to numerous dealerships and mechanics but no one seems to hear it. It sounds like metal clinging or a change dragging sound?!? Anyone else?

 

Maybe something is loose in your doors?
my dads Colorado had an annoying rattle;
maybe a window piece got loose too

 

When do you hear it? Sitting still - accelerating - decelerating etc ... Maybe post it for all to hear

 

I have a 2007 Tahoe that has a strange "metallic" noise too. I have no idea what it causing it, but I only notice it when the truck is moving forward. It kind of sounds like a chain "clink", but it is not a suspension "squeak", and not a rotational sound like something the brakes would make.
I have a feeling it's some metal bracket that is loose or partially disconnected under the truck, maybe in the spare tire area. One other thing I'll check is the interior compartment where the spare tire tools and jack are kept, maybe the things are loose, however, it doesn't sound like it's coming from the interior.
Sorry I couldn't help, but at least you're not alone.