water on floor right rear footwell

[stackz]

was cleaning the carpet today to put in my new floormats on my 01 and when I was cleaning the right rear floorwell I realized water had gotten in. an area from the right rear corner by the door opening up about 3" and over about 6" was wet...not sopping wet but wet. I know I will have to pull up the carpet and cut out the jute underneath so completely dry the area but before that...

I'm trying to figure out how its getting in?

I grabbed the hose and put it on jet mode and hit the whole door all around and in weird angles just trying to simulate splash and such.

only place where it was weird was on the actual body weatherstrip at the bottom middle. it was kind of pooling up on top of it. It also started to come over the top of it and go down the trim piece towards the carpet. ok...

I looked up under at the door itself and the bottom of the door panel in the same area had water on it.

I mean both body and door weatherstrip are intact so the only thing I can think of is that age has gotten the better of one or both of them and they are allowing an air gap but the car isn't that old. I guess it "could" be depressed since I think the previous owner kept a child seat on this side from what the seat bottom looks like (can see depressions in the leather from child seat continued contact).

but wouldn't the driver door be more logical for this to occur since its used much much more often??

anyone with similar? or advice on what to look for?