Pano roof?

 

In a garage or under a carport? Where I live, every fall when it starts to get very cool at night but still warm in the day, that will happen if the vehicle is parked out under the stars. Being under some kind of roof prevents it.

 

Exterior or interior of glass?

 

No sunroof. Parked outside with no cover. It’s on the inside of the glass. Never had a vehicle do this that I can recall.

 

As a precaution you may want to lift up your carpet & look for moisture....also check on the back wall. Some trucks have experienced leaks around the third brake light or windshield

 

I've had this happen a couple of times on a car when it got wet inside, say from leaving a window open when it rained, or from snow melting through the fresh air vent on the cowl. Or as Firerunner said, because of a leak. On the next sunny day park it with all the windows open in a sunny spot and see if that helps.

 

 

Fill a sock with cat litter and put it under the seat, the cat litter will absorb moisture in the cab - I had to do this when a cooler full of melted ice turned over in my truck

 

I think the neighborhood kids are using your truck for necking....