Do you have a sun roof? It can be leaking from there.

Check your ac drain tube. It’s under the carpet on the passenger side. When it clogs, water can back up.

 

sorry, I should have specified at the beginning, no I do not have a sunroof. I checked the tube and it was not loose, very firmly connected. So
you're saying I should disconnect it and check if it's clogged? Is there an optimal way to do that or would I just pull it loose and poke around inside? Where does it drain to so that I can check on the opposite end of it?

 

Do you have a luggage rack? And is this happening after it rains/ car washed or is this happening without the outside of the car getting wet?

 

no luggage rack and yes it gets worse depending on how much it rains, I am constantly wet vaccing it

 

Are the door drain slots clogged. Are there any drain plugs near or under the bottom of the doors?

 

Ya, the water is leaking in from somewhere, you are going to have to get that carpet and foam/insulation layer up and get everythign dried out, or you will end up with a permanent musty smell. Video here to give you an idea Could take a day or days to get it to all dry out, hopefully you have a garage you can do this in so you can have the doors open, have it out of the weather and have a fan blow on it. And you need to find and fix the leak. I have heard of the corolla getting wet carpet from a failed seal on a tail light, the water gets past the seal, leaks into one of the holes in the frame of the car and flows to the floor board and carpet. Could be a seal on your windshield, rear window, etc. If your car has rust, if you live in the rust belt, you could have holes in the floor board where watter is splashing up and getting into the car. I see some of the 2004 corollas have the exterior antenna on the rear of the roof? That could be a source of a leak if the seal has gone bad over time.

The most common reasons I am coming across are a bad seal on the tail light or clogged up drain ports.

Check all your doors, open each one and wave it back and forth to see if you hear any sloshing, if so, might be a clogged drain at the bottom of that door that needs to be cleaned out.

Another common leak area on some cars, not sure if true for the 2004 corolla is at the top of the windshield, on the corner where you have the groove on the roof with the plastic trim where it comes down and meets the corner of the windshield.

You should have rubber pugs on the bottom of the car you can pop out to help drain the water, can be removed from under the car so you don't even have to pull up the carpet to get to them.

Other videos that might be helpful in your search for the source of the leak

Pics

 

Report back when you figure it out.

 

I took out the rear seats and noticed a wet spot on the back cushion portion where at the very bottom it was wet as if there was water traveling from the trunk into cabin of the car through there (where the trunk meets the back seats). I use this car for commuting and almost never use the trunk so I checked it for the first time since the summer and I noticed it was wet on the inside. Not sure exactly what is letting water leak in but the most noticeable detail was water on the trunk hinges, and the entire bottomside of the trunk wet with water drops (not sure if this is due to condensation and the leak is primarily traveling down the hinges). My first thought would be tail light gaskets? Is there any other way water would be traveling into the trunk lid and down the hinges?

 

IME, a good auto glass shop will test your windshield for leaks and fix for nominal charge. Usually a PU gasket material. But, that product has shelf life concerns and takes time to set up. So, if it needs resealed, listen to shop, obviously.

Unfortunately, I've also discovered a replacement windshield like eight years ago wasn't too bad for my 04 Canadian built CE. Shop said no used glass back then, so a broken windshield common for 9th generation?

There's also the possibility of a buildup of bio material can prevent the proper draining of water from cavities at base of windshield. Was bad on a non Corolla, 8 years old car. Discovered by my glass place. That car had some plastic trim pieces that were fragile and needed replaced.

 

Drip rail trim clips are installed under the front and rear windshields. It’s possible those are no longer sealing. Weatherstrip trims cracked and torn up due to sun damage.

Try the water test and go to each corner of the drip rail and pour water. Then do the same for the top of the front and rear windshields.

 

I turned on the hose and let it spray all over the rear glass and trunk area, the stripping around the trunk wasnt leaking and diverted water like it should, where exactly under the rear windshield would the trim clips be? Would that cause water to drip down the hinges and into the trunk?