Ok so I just got a 2018 Lt2 RS with only 8182 it was always garage kept and driven on sunny days. So this past week I noticed the windows were foggy. So I knew right away I had a leak somewhere. It was damp under the driver floor mat and wet under both seats. The dealer has had the car for a week. They have done a water test on the windshield, sunroof and checked the AC drain and found nothing. Does any have any ideas where it may be coming from?
The trunk is dry a a bone.

 

wow, I guess that leaves the doors and the floor,,, have you dried it completely and tried to track it

 

That's crazy, on a 2018 too.