I had a water leak in my 2001 Focus wagon, but it would collect in the rear passenger side floor area. Turns out the water was leaking back there from the front. The water was entering into the cabin area from the rear of the front passenger side fender into the floor area, leaking around a grommet for a major wiring loom that wasn't quite sealed well enough to the sheetmetal. The water entering the raintray area would, by design, leak sideways into the fender area, and then trickly its way down past the grommet, and some of that water would enter the passenger compartment area,
I remember removing the passenger fender for access to the loom and grommet. Removal of the grommet was not feasible, so I tried re-seating the grommet better, and sealed it additionally with silicone.
I found the location of the leak by peeling back some of the carpet, and tracing it's way upstream. Spraying water on the windshield would trigger the leak.
I'm not sure if this is your leak of not. It was quite aggravating to find, but I am so happy to have a dry car now that it's fixed. It was horrible, with standing water back there, and fogging all the windows up all the time. Now completely dry. Good luck.