Butler has made some calls...
Some big wig GM types were to hold a meeting yesterday or today and my situation was to be a major topic of discussion.
Had the son in law winterize and return the van and
Butler to the dealership again (took it back for a couple hours) thing rattled like an old tin can and yet my dealership just can't (not sure how enthusiastic) find the rattle.
I am calling again Monday.
Thinking I will suggest they pull the oil pan of the motor next to look.
They told me the region rep would be back again on Feb 22nd....

good grief...
Just need permission to take it to a non GM mechanic such as my brother in laws shop so we can find it.
Also called a body shop friend of mine to put it on the frame rack and test it for out of square problems or cracks.
Right now just no one wants to find the problem.