Buick Repair Questions? Ask a Mechanic for Answers ASAP
This is a comon problem on this car. there are two places that this leak will be coming from, the windshield seal, or one of the joints where the body is put together and seal with seam sealer.
To be able to find this leak, you will have to pull the carpet up, remove the kick panel, and pull the glove box out.
this will make it so you can see where the water is running down from. The reason the front of the seats is the only place there is water pooling up is there is a low place that runs down the side of the seat. This will keep the carpet dry under the seat as the water is running up under the carpet down this chanel and to the back floor board. There are frain plugs in the floor board that you can remove to let the water out of the floor board area so it can dry. You will have to pull the front seats, and seal plates tp remove the carpet, as well as the seat bolts where the bolt to the floor.
then just run a water hose over the upper corner of the windshield till you see water running in, then lower the water hose till you do not have water leaking into the car anymore. When you get to this point, the leak has to be just above that level. If the water stops leaking when you lower the hose below the windshield, then the problem is going to be the seam sealer cracked and it will need to be resealed.