Well after my issues with water ingress into both my pass and drivers side footwells I thought I would post this to help others since I have now sorted all of the leaks !!
The weekend after collecting the car I started looking into why the carpets were soaking and found all the usual posts on here about various things to check.
The passenger side leak was an easy enough fix as like many others the water was coming in through the pollen filter due to the scuttle panel not clipping into the bottom of the windscreen properly. I solved this by making up two sheets of laminated A4 card and wedging them under the windscreen then bending them down over the filter and into the scuttle before refitting the plastic scuttle cover. This now means any water coming in under the plastic cover runs down over my laminated card and drains away as normal rather than dripping down into the pollen filter.
With my carpet fully removed and hanging up in the garage to dry for 3 full weeks I needed to locate the leak from the drivers side.
After being almost certain it was due to a replacement windscreen not being bonded in correctly I was astounded when I managed to spend some time on Saturday investigating this issue further and found the cause of my leak which has meant me running about with no carpet since before christmas !!!
When it rained or when the car was washed you could see water pooling down by the accelerator pedal and it looked like it was running down off the side panel next to the kick plate. I stripped out the under dash panels and removed all of the fusebox wiring connectors to allow me more access to see if I could find out where the leak was. even after removing all this stuff the sound deadning was still hiding areas the water appeared to be coming in from so I removed this as well.
On removing the sound deadning I noticed it was soaked through so knew I was definately in the right area. I then got my dad to hose the car whilst I lay on the floor under the dash with a torch. Next thing I know I have water pouring down onto me as expected but it turns out it was not coming in at the A-pillar but actually running down the bonnet release cable and through its grommet !
I stuck a cable tie round the grommet neck and tightened it against the cable and bingo ! no more leak even when blasting it directly with the hose.
So folks, check your bonnet release cable is nice and tight where it goes through the bulkhead grommet if you have water ingress ! Mine had been stretched as someone previously had a boost gauge installed and had run the hose through the same grommet which meant when it was then removed the grommet was no longer able to seal.
The result was that I was now finally able to refit my carpet and all is good !
Oh and the reason it took 3 weeks to dry out hanging up in the garage was that it had soaked up nearly 14 litres of water !!!!