I have experienced the same leak in the upper corners of new AT4. Less than 3000 miles. My dealership tried to fix it twice with a bead of silicone. Not the right fix. Looks terrible and still leaked. Felt helpless when dealing with them. Then it was sent to a supposed glass specialist. When I got my truck back the rear headliner would stay in place and there was a 12 inch scratched area of paint An inch wide scratched away on the roof above the third brake light. This specialist had scratched the paint away to the metal. My truck is now at the paint and body shop for repairs on a brand new truck. This sucks!!!