Hey everyone, 2020 Crew Cab Rebel owner here - build date Oct 2019. From the day I bought my truck, the rear window frame had a mark on it that looked like it had a microscope crack or was on the verge of cracking. Well, temps hit the 30s last night and we have had days of rain (not typical in SoCal), and this morning when I went out to the truck to grab something I noticed the interior of the truck was very humid. Felt around and noticed the rear driver side corner of my headliner was damp, then noticed that the stress mark was in fact now a crack. I called the dealer and was told to wait until Monday to bring the truck in, so in an effort to not have my $60k Rebel smell like mold, I took the heat gun out and dried the headliner. In doing that, the light heat (less than 100 degrees F at the site of the crack) seemed to cause the plastic window frame to expand and make the crack visibly disappear. So, I took some compressed air and got the frame cold again, and the crack was back. So, what I've gathered from this experiment was that the plastic used to make the window frames has considerable expansion/contraction properties in typical environmental temps. Far too much for something that should be glued in place and stationary on a vehicle. The manufacturer needs to utilize a different polymer that is more robust to environmental temperature changes.
Now, what I'd like to know, is why do all of our window frames crack in the same location?
