Passenger side front window pillar and seat belt pillar soaked

Hello thanks for using 2CarPros. It sounds like the door seal is leaking or the sunroof. Looking at pictures, does your car have the 2 sunroof set up and did they check to make sure they're sealing correctly? Just an idea, try spraying the car with a hose at certain points and have someone sit inside and watch for a leak if you have it apart already.

Okay, I'm just wondering, does you car have those small vents on the front hood? Open up the hood and look up at the top left of the engine compartment, this would be the passenger side. Now I am just going by pictures here, is there a possibility, while driving faster and its raining that water is streaming up threw those vents. This is just an idea since you already have someone trying to find the leak.

Okay, it found something. Buick has supposedly 7 recalls for water leaks on these vehicles. You may want to take the blower motor out, under the passenger side dashboard, and check for water as well. These can fill up with water and cause the blower motor to fail as well. Now, "they think" it's coming in either the sunroof or from underneath the vehicle. But I would check the blower just to make sure it's not sitting in a puddle of water as well. It comes out pretty easy.

Also check that the A/C drain hose is not clogged. It should be visible under the car on the passenger side. This may also be an issue. Try to stick something in the A/C drain hose and makes sure it's not clogged. I know this doesn't have to do with the leak from the upper passenger side but it's worth checking. This is also a picture I found from the Buick recall for water leaks.

There is an updated seal for the sunroof. This may be the issue while driving, since air is pushing on those seals at higher speeds.

This may be an issue for a dealer to look at and diagnose. Not a body shop. The dealer will have the correct technical service bulletins.

Well if it's a design flaw, like the chassis not being sealed correctly or a bad sunroof seal, it's something they will have to repair. There is a lot of these cars doing the same thing. I'm trying to find as much information as I can for you.

There's information about windshields not being properly installed, drain hoses for the sunroof that are too short and should be updated, creating a water leak into the sunroof tracks. An updated sunroof seal, and something about the drain hoses not being straight, having a drop causing water to back up and puddle.

If they really can't find anything, I would focus on those drain hoses. I'm so sorry this is such a bad issue. It's frustrating a lot of people.