Can anyone tell me if they have had a rattle above the driver side wind shield
if so what was it? Have no moon roof. The old service rep said it was the
trim but the new service rep said he has'nt seen anything on it. not the wipers

 

is it a rattle or a chirping sound? if it's a chirp i would look at the pillar moulding(the trim that runs from the dash to the roof inside). sometimes if that is touching the glass it will make noise as the trucks twists and it moves against the glass.

also it could be the cowl trim. all of this stuff is just snaped and clipped on these days so it can very easily become loose and move around.
good luck!

 

This is at highway speed going stright down the road out side the truck

 

From what you wrote first I take it that this noise seems to be coming from overhead. If this is correct I would check the side windshield moulding. If you havent allready noticed, it runs completely across the cab to the rear corner. This entire piece is held on by only 4 clips along the w/s and a "grip-strip" along the roof. All plastic and easy to damage and become loose.
Simple test, cover the entire strip with some type of tape and drive it. If the noise goes away start removing a little tape at a time until you find the exact source.
It is possible that the top w/s moulding could be rubbing wrong against the body. Highly unlikely with that style trim but not impossible.
These are the only things outside to check on the roof, if this doesn't reveal the source you might want to start looking internally.
Do you have vent visors installed? (just a last munite thought)