!991 buick park avenue. the trunk fills with water during heavy rains..resealing rear window didn't help..where in the heck is the drain plug for the trunk..if any?

I used to get water in my trunk when it rained hard. I re-caulked the rear window and it stopped. A water leak has a capillary effect meaning it will follow ridge lines and can appear in unlikely areas after it flows downward. I sometimes get water on my driver side door when I wash the car and spray sideways to rinse. I would check all your rubber seals around the windshields and doors.

several qs. What year make and model is the car? Is car level when water fills floor? Does it always happen every time it rains fairly heavily? Is the trunk always dry? Talk to other owners for their experience.

I had this exact same problem when ever it rained with our 1999 Range Rover.
Even the spare tire area in the back filled up but didn't know it until I got a flat tire.
Two things were wrong.
The sunroof leaked and we didn't know it. Also the seal all around the frontwindshield was not sealed tight but didn't know as neither of these were obvious. We ended up using "duct tape all over the roof around the sunroof and I meen a lot of tape! It looked bad from the sky, however stopped leaking 100% Dont use the sunroof if you have one until summer, remove wet tape periodically and inspect. Hope this helps! :)

After it rains have you noticed and water drips that might give you a clue as to where the water is coming from? It might be leaking around the base of the back window. Does the water come in only when the car has been driving or does it come in while the car is parked? If the water is coming in while its parked then there is a hole somewhere on top, probably around the back window, and is running into the trunk. When its raining or after it has rained look in the trunk and see if you can see water droplets and this should give you a clue where its coming in. You can also hose the car down yourself. This might be a good idea to try when the trunk is dry so you can see what does and doesn't allow water in the car. Try running water on one side at a time. If it only seems to come in after you have been driving the car, it may very well be coming in around the wheel wells or around the gas fill pipe. Look inside the trunk and see if there are any rust spots and use a flash light to see if you can see any holes through the metal. take a close look around the sides on the floor of the trunk and see if there are any pieces of rust accumulating, this might help direct your search for the hole. You may also want to look behind the tail lights and see if there is rust damage. Check the seals around the tail lights and see if its getting in that way. Look behind the licence plate for rust damage as well. Try those things and see how it goes. Good luck.

The gasket between the light assembly and the body is a poor design and lets water into the housing when it rains hard after it dries out after a few years. Taking the lights off and replacing the gasket or adding sealant may help. I drilled a small hole in the bottom of each plastic housing for the water to drain out and resealed the lights too. Any water that gets in drains out the tailgate drain holes. Problem solved.

I have a 1993 ParK Avenue, the original owner said that when she purrchased the vehicle new in 1993, she has always had water getting into the trunk, I found water in the passenger rear floor and I assume it is through the trunk, I had water in the trunk, I drilled holes in the trunk , also in the floor of the passenger area, Yesterday I vaccuum the car and the passenger area was dry, I think a little water may enter the trunk but it will drain before it reaches the interior.

Mother nature is too slow in finding leaks. Have someone small get in the trunk with a flashligh and watch as you run a hose over everything. LET THE PERSON OUT!

there are drain hoses on all all four corners of the sunroof. to access the front ones, remove the front inner fender liners. you'll probably see a plastic grommet/spout that the drain hose attaches to. in the rear, remove the trunk liners on the side. you should see the drain hoses running down the inside of the quarter panel.

sometimes the window weather strip isn't air tight and it could get in your door panel.

I had a similar issue and found that the two rear drain holes for the sun roof came off and any water was running down into the trunk and also the rear floor was always wet. I pulled the rear of the roof panel down to expose the rubber tubes, re-seated them with glue so they would not come off again.