OK I figure I will try the THIRD GEN forum and see if I get any results. I have a 2001 Cavalier 5-speed manual coupe base with a rear spoiler sitting on top of the trunk. It has 232K miles and a bunch of ongoing mechanical problems. And while I need help on those things, the most pressing issue of this really bad new (started in the past 2 months) leak inside the trunk. Now let me say first that I have already had and dealt-with the vent leaking (this leak is not coming from the vent on the passenger side), AND the tail lights (I have permanently fixed that too and this leak is not coming from there either). Finally, yesterday, I happened to be inside the car when a REALLY bad / heavy rain storm spent an hour right on top of my location. So I pulled down the back seat, grabbed a flashlight and - with extreme discomfort and difficulty - tried to position myself so that I could see where the water was coming from. I had *just* (in the previous 20 minutes) completely dried it out so there was no water anywhere when the rain started. I fully expected it to be dripping from one of two places - either from the spoiler bolt hole openings, or more likely from the main weatherstripping seal. Much to my surprise and puzzlement - it was neither. No water at all was coming from anywhere around the entire trunk. Not the sides, top or back. Not from the tail lights. Instead of dripping down, it just seemed to gradually puddle up mysteriously from some place that I could not see. It eventually puddled so badly that within 10 minutes of the rain starting it was a full on pool of water that had filled up all of the depressions in the steel molding on the bottom of the trunk (I have taken out the padding and most of everything else in there). After trying to figure out GENERALLY where it must be coming in from, I have narrowed it down to the driver's side way forward of where the trunk is - really closer to the rear (sealed) window. This 2-door has windows in the back that cannot be opened. The leak must be coming from some place around the driver's side / REAR roof support that runs from above the left rear wheel well to the driver's side door on top.
I am desperately hoping that someone with a car similar to my model knows what I am talking about and where this leak might be from and how to stop/seal/fix it because all I can see is the water gradually pooling but cannot see where it is coming from. I can't even get my head into that extreme left side of the interior of the trunk. I don't know what to do.
Any help would be greatly appreciated.
Im in the same situation. I had a massive water pool in the botom of my trunk. To date ive changed the weather strip, sealed the tails and air vent. Went around every crack/lip edge i could find inside and out with silicone. Sealed the latch piece. Had my window pulled and resealed. Removed bumber and went around every place inside and out possible with flex seal and undercoating, u name it. Still a small leak. Weird thing it leaked in all of the above places and when i got to 2 leaks is when i had the window redone. Leak stopped on the side it was leaking but started on the opposite side.. My guess is its running down the track at the rear quarter glass and into a weld seam hole. My fix, might not be proper but at the wheel well edge where it looks to be leaking in i took a piece of aluminum and boxed it off from the rest of the trunk, drilled a hole to release water. Seems to be working. Mind u tho my whole inner trunk is lined with undercoating to help protect it from rusting. Also serves as sound dampening
Thanks for the reply. After thinking about it overnight, I realized that my problem is likely the result of years of having to slam my driver's side door to compensate / deal with the worsening sagging. You can read about that from my old post about it (there's probably several related posts scattered around about door pins, etc....):
Anyway, the points where the driver's door impacts the body of the car when it is closed (and it never closes unless it is really slammed hard) are mainly that section I described yesterday - the roof support or section that runs above the rear driver's side window back to the wheel well. So my theory is that all the repeated (probably about 20 times every day for YEARS) slamming has cracked open the metal under that relatively weak section of the car and that's where it is leaking. Assuming I can confirm that the leak is coming from there - when I pour a glass of water into that opening around the black rubber that is between the back windshield and the driver's door along the top - the next puzzle will be how to seal a hole that I can't get to. *ugh*