Arg! Water (still) coming into driver's footwell!

Many of you have followed my quest to rid my 300td of leaks. The sunroof drains are open and draining OK. Still, if the car sits outside in a hard rain there is a little water in the driver's foot well. It's already starting to corrode the new metal I had welded in!
Window was replaced last year and it's been back a couple of times for re-sealing but primarily up on the corner near the A-pillar.
I feel the carpet to see if it's wet anywhere but it's really not, it's just when I peel it back that I find the wetness.
I suspect that the water is coming in at the bottom of the window, dripping down the firewall near the pedals, and into the footwell?
This is only after rain so I do not suspect the hose which has been discussed on the forum.
Am I on the right track?