Sunroof leaking

Hello, I'm Danny.

Here is what I've found for your Buick. I've attached the pictures below. Hope this helps and thanks for using 2CarPros.

Danny-

Hello again.

As you can see by the pictures I've attached there are front and rear drain. Hope this helps and thanks again for using 2CarPros.

Danny-

Welcome back. For these they don't show a lot of information. However they are not that difficult, the trim around the edges gets removed enough that you can lower the headliner just enough to reach the drain hoses. As it is leaking at both points I suspect the hoses have come off both drains, There are three drain connections, one goes down the A-pillar and a second one Ys together for the rear drain that goes down the C-pillar. I would suspect they either got plugged and the water is draining out the sunroof itself and down the pillars or the hoses came off when someone attempted to clean them out, both are very common.
The pictures tell more than the information does.

You drop the sides of the headliner by removing the trim enough that you can get to the tubes. Or you can try the drain snake method. Get a long piece of somewhat stiff wire or weed whacker string, the heavier stuff. Then you feed it through the drain ports that are in the corners of the sunroof. Sort of screw it down through and it will clear them out. On some you can find the lower ends of the tubes and feed it up through to clear them, that actually works better sometimes as it doesn't try to force the clog in harder.

Most of the time you don't need to fully remove the headliner to get to them, you remove the trim down one side and gently pull the headliner down to get access. Clean the drains and put the trim back, then do the other side.

Correct, As it states in the first image, you need to remove the trim around the edges. That means the pillar trim. However you don't need to remove all of it at once, you should be able to remove only the rear trim and to the front door. Then lower the headliner enough to get to the drains.

About the only places they normally leak are the drains. However they are not really well sealed so I would look at all of the seals and tracks to be sure it does close as well as it can and that the water can actually drain, use a water bottle and test that they work while you watch it. Next I would look at things like the roof rails and rack areas to see if there is an issue there. Sunroof leaks can be a real bear to find if they are not in "expected" areas.