dpease

Help diagnosing the issue please. I've been to GM dealers and mechanics that can't seem to find the source of this noise. It seems suspension related and mostly towards the rear. The noise is easily replicated ESPECIALLY WHEN THE TEMPERATURE IS ABOVE 20-30 DEGREES! That's the key if its above freezing the noises occur consistently on bumps. It is a loud rubbing sound that the GM people tried to convince me it was a BODY issue but I haven't been back sense noticing the effects the TEMPERATURE has on it.
After 4 visits to the specialists I believe the only thing to be replaced was the lower control arm and some grease to the body mounts. Any thoughts PLEASE?