I started finding water in the trunk of my 2016 coupe/fastback. Once I pulled out the trunk panels, I found the sides were full of water. The issue was finally tracked down to the seams at the top corners of the rear window opening. Once I was aware of this issue I started looking for it on other cars, and everyone of them is in some stage of failure, with the seam sealer splitting open. While at the dealership service center at advantage Ford in Stuart, I noticed a gt350. I looked at the seams on it, and they were split open worse than mine, and even was showing cracks in the paint and bodywork of the driprail in these areas on both sides. I looked at a co workers 2017 ecoboost...same thing. This is a $1500 repair if out of warranty. Everyone needs to look for this issue....to me here it Florida, it seems extremely widespread, especially on non garage kept cars. Mine is just out of warranty, and I'm trying to get Ford to help me out since it is obviously a manufacturing defect. Check your cars for this people.