I removed the roof trim when its rubber started coming apart and curling in the sun. I couldn't figure out a normal fix to keep it on. All other Calibers in the junkyard had the same problem.
Once removed, I also took off the plastic clips and plugged up the holes with plugs (huge PITA, like 13 per side).
I didn't like the bare look, so I also masked then painted the area with spray-on bedliner. From a distance, it looks like a stock Caliber.
Maybe this is an option for others?
This is the only car I've owned that seems to dump any water on the roof down the windshield. Turn left, nothing. Turn right, nothing. Hit the brakes, everything down the front.
I found an aluminium carpet strip - to transition from carpet to vinyl. After some bending, I siliconed and screwed it onto the top in a way that would catch the water and channel it off the sides.
Works great for me, may be a bit odd looking on your vehicle if it doesn't already look odd, lol.