Discovery 2 front passenger footwell water ingress

I appreciate it's been done to death but this really has me scratching my head.
Lots if water in passenger footwell.
Pulled carpet and located 50p piece hole in bulkhead so I've fibreglassed that up and siliconed around that area and around the rubber grommet running the wiring through the bulkhead.
Gave self huge pat on back for being so clever but water still running down inside of bulkhead into footwell.
I've had the bonnet off and scuttle trim and there doesn't appear to be any area's of issue.
Any idea as to the source of the Nile?
It doesn't appear to be coming from the A pillar so does that rule out any problems with the sunroof?
Cheers

Hi,
I’ve been on this recently too, except the hole in my bulkhead is more like a fiver in size...
other things to check would be heater pipes - there’s one each side of the centre console, push fit ones.
Leaky heater matrix?

The bulkhead/floorpan and inner wing meet in a triangular joint which rusts through. Have a look under your wheelarch and poke around under all the crud and you will find that a screwdriver will go straight through.