This is the second winter that the passenger footwell carpet of my 2009 Skoda Fabia has been wet. I am not sure what is causing it, and would like suggestions on the most likely things to investigate. The fact it issue has only been noticed in winter suggests that it is rainwater related.
I have already:
Checked the passenger door - I had read it could an issue with water not escaping the inside of the door correctly. I took inside fascia off the door, expecting to do a repair like this (https://youtu.be/o1d5L5rX2Oo) but it appears that in my model (2007-2014) the water is no longer channelled through the door behind the fascia.
Checked the pollen filter I had read that this being blocked could be responsible for this kind of issue. I removed a small amount of debris from the filter, but the filter seemed in reasonable condition.
Checked the rear window washer I had read that the line for the rear window washer is under the passenger carpet, and it being damaged can cause damp carpet. Apparently you can tell if this has happened because the rear wiper washer doesn't produce much water. My wiper sprayed fine, also if this was the issue I would expect the car to smell like wiper fluid.
Checked the door seal I poured a bottle of water over the join between the top of the roof and the passenger door. I got in via the driver door and couldn't detect any water around the inside of the passenger door.