Most likely your lift point is so rotted out that the water is being absorbed into the foam under the carpet. When I took out my carpet the whole thing and the insulating foam were soaked!
You can remove the knee bolster (panel under the steering wheel/dash) and see if there is a rust trail from further up under the dash... that could mean the corner of your windshield is leaking. One time I had a place change the windshield and then realized 6 months later that when it really rained it would leak. I pulled the plug strip out and resealed the window as best I could with black RTV then put the strip back in.
The sunroof drains don't go into the car, they go out to the rocker area through tubes.
The vents below the window have drains in the engine bay. It is possible that is blocked and leaking although I've never had that happen.
#1 You have a hole in the floor.
#2 You have a window seal issue.
#3 You may have a heater core issue, but that would smell like coolant.
Performance one step at a time.