2007 Honda Accord floor wet?

Our 2007 Honda Accord V6 Manual which we got used a few months has another problem. Between the power steering failure and the third gear spit out, we just can't win. This time the rear passenger floor is soaked. The carpet was literally black, as opposed to the tan carpet around it.

I vacuumed it out with a shopvac and more water was in there than there should be. I'm currently letting a fan dry it out. Is it a door leak, some sort of fluid leak? I read that the AC dropoff might come through the carpet. But the water was soapy.

What is going on and will Honda cover this?

It is a 7 year old car. I doubt it is still under warranty.

Check your trunk for the leak