Water behind passenger seat.

[pomerlo]

I have read somewhere that water can enter from the door.
What if you pour some water between the window and the door ?

[BirdDog]

I'm no expert, but like pomerlo said, it's possible it's coming in through the door. I believe there is a water shield (sheet of plastic) that has a bead of sealant around the edges. If the bottom edge isn't sealed, I think water can enter into the car through the unsealed edge. Have you had the door apart recently (to change a window regulator, fix a door handle, or mess with the door speakers)?

[rexcramer]

+1 on verifying the door plastic sheet integrity. I experienced that problem. Any chance the firewall cover and/or gasket are not tight? Do you drive in the rain?

[Syracuse986]

Originally Posted by pomerlo

I have read somewhere that water can enter from the door.
What if you pour some water between the window and the door ?

Is there a picture of where this fail point is on the door/window? Does it come in through the top of the window or the bottom of the door?