Scotty,
I just bought a 2007 Toyota Matrix with 94k miles. A lot of water accumulates on the passenger side floor after it rains. I looked at the ac hose and it's still attached. The door drains are not clogged. Any ideas?
Do you have sunroof?
no sunroof
Check the passenger door seal and window.
Could be the windshield gasket. Use a garden hose to soak suspect areas and look for drips inside. Another approach is to run the HVAC blower at full blast and spray soapy water around the windshield gasket etc. the way you'd look for tire leaks.
Put a dollar bill in the door and shut it. If it moves around loosely, you need a new door gasket. If it's tight, keep looking.
Thanks for all of the helpful suggestions. Turns out it caused by the cabin filter. The previous owner had installed one that was too big and squished into place. Since I've put the correct one in, I've yet to have any leaks, despite loads of rain.
