So many good theories. I guess that is why the mechanic makes the big bucks!

Thanks everyone.

Had this exact problem. Drain was clogged and water backed up into car after heavy rain. Could not be unclogged without taking pieces out under hood so had to pay for it. Never happened again.

I have been having this problem, too, and can't figure out where the water is coming from. How do I go about "unclogging"?

Probably a clogged sunroof.

Anonymous wrote:What make of car is it? I know some Mercedes can get flooded in the passenger compartment after a heavy rain when the water vents get clogged.

Honda Accord (which I have had for years, with no prior problems)

What make of car is it? I know some Mercedes can get flooded in the passenger compartment after a heavy rain when the water vents get clogged.

Never thought of that!

I had water issues for 2 years. I suspected the windshield, as it had been replaced, but they swore it was the sunroof. Sunroof people swore it was the windshield. 2 years and a lot of tarps/ bungee cords/ shower curtains later, I discovered it was the windshield. The people who replaced it years earlier had to pay almost $5k to replace the headliner, stereo, and actually seal the windshield.

Have you been driving with the ac on? Sometimes the ac drain can get blocked and cause the floor on the passenger side to get wet.

Anonymous wrote:The drain seals those leaves would have theoretically been blocking are probably bad. Replace those and you should be good.

Thank you.

To the PP, I don't have a sunroof. And I checked that the window had been completely closed.

Just wondered if that HEAVy rain go into somehow..but it seems unlikely. It is not like the car was parked in a flooded street. It was in a parking lot with drains.

The drain seals those leaves would have theoretically been blocking are probably bad. Replace those and you should be good.

Do you have a sunroof? That’s what caused it for me

For the past few months, if it had rained hard, I heard water sloshing in the front left if my car when I drove.

I read online that leaves could be blocking drains. I did find a lot of leaves at the base of my windshield, so cleared them away. That was maybe a week ago. No noise since, but I have not been driving much.

Today when I was in my car, I noticed that my floor mat on the passenger side was wet, and had a little white fungus growing.

Recall we had record rain a few days ago.

1) Do you think these two stories are related?
2) How did my floor mat get so wet?
3) what should I do now?

Thank you!