I'm installing a camera in the rear window, and while I was running the wire up front, I saw about 1/2" of water on the floor of the driver's area - under all the carpeting. I have no idea how that much water could have gotten in there, but I'll have to check the next time it rains. I vacuumed out as much as I could. Now I'll have to put kitty litter in there. I'd rather not remove the seat to remove the carpet, but it might come to that.

 

could be coming from clear plastic sheet that's supposed to be sealing off the access holes in the door's inner sheet metal . this has been a problem area
on some fits . there are some threads about it in the archives . you have to remove the door panel to take peak in there . if it's coming from there , you'll see water filling up the
gutter ( below the door ) in the rubber seal that goes around the entire door opening . the water seeps past the rubber caulking they use to seal the plastic around the openings in the door's sheet metal .
you could try a heavy spray of water with a hose at the driver's widow , see if water will start accumulating there .that is a lot of water though

 

Thanks. That will be my next project - after I get the car put back together.

 

My wet floor was caused by the sunroof drains being clogged.

 

We had heavy rain, so I'll have to check the floor. I don't want to have to lift the carpet again, though.

 

How can you check those? I went to the dealer with water on the floor and first-hand experience of SEEING water come through the headliner, and they still wanted to charge me an arm & a leg to do an "investigation" to see if it was coming from the door.... UGH. Wet seat, 2" of water on driver-side floorboard.

(My 2nd Fit: steel metallic 2018 Fit EX)
(My 1st Fit: blue pearl 2006/7 Fit EX)

 

Watch this about moonroof drain cleaning:

"2 Things That Damage Your Car This Fall Season and How to Fix Them!"

The guy is a Toyota technician, but as he states, the mechanism is pretty much the same for many other designs.

 

Unless the car is under warranty or it's a recall, I'd avoid the dealer. The dealership is nothing but a giant money vacuum. Ask around and find a good local mechanic. A friend brings her Honda to a local guy. He does excellent work for fair prices. She brings him baked goods occasionally.

You car could have one of those rare situations where water leak in through the door and then travels up to the headliner.

 

I do not disagree with anything this guy says, but when you take 21 minutes to explain a 10 minute repair, you are doing it wrong.

 

At least his video didn't have a 30-second intro. Lots of YouTube people talk too much. That's why I appreciate being able to fast-forward.