I found water in my rear doors last year and figured it was because it rained while I had the windows partly down. Now I checked again and they are full again. I would say a few inches in each door, pulled the trim and the water shoots out. Check all doors, they don't have drains. Also my freshly painted tailgate inner seam is already rusting again. :mad::mad:

I've noticed my tailgate seam is starting to rust. And the truck seems to scratch just by looking at it.

In the past GM always considered the interior of the door to be a "wet environiment". Therefore you always had the plastic liner on the inner door panel and drain holes in the door bottoms. I wonder if they tried to change the door environiment????

Have you checked really well around the door seal to make sure it is not hiding the door drains? Run your hand along the seam on the bottom of the door to see if you feel any drain holes. If they are there whey would be along the outside edge of the door seal.
John

just had the same issue with mine, open the rear doors and remove the weatherstrip on the bottom. behind it is two oval drain plugs. just remove them and put the weatherstrip back on. i must have a few quarts of water in mine.