After a bit of looking around I still can't find the source of the leak.
I laid some tissue paper in some spots to try to pin point if there was any moisture.
Here's the driver's footwell. The tissue at the front closest to the firewall is dry and was never wet. The rearmost tissue is quite damp. It sits over the rubber floor bung.
Passenger side firewall. I thought this may have been a source of the leak as on the other side of the bung is the felt liner on the inside of the cabin.
Passenger side showing where the water flows.
Drivers side firewall with the elec grommet. Thought maybe water might get in thru here but it was dry on the cabin side of the grommet.
Where water flows when wet.
Thought maybe water might flow from the rear door but this tissue was dry.
Could it be condensation coming in from the metal floor skin? The drivers floor bung looks secure but not 100% it's not coming thru from there. It is in the same spot as where the moisture is though.
Any ideas?