I have searched and found loads of threads on water in front foot wells but mine is in the back behind the drivers seat

So I cant see it being windscreen or pollen filter or this leak on the bulkhead

Any help welcomed

Have you got a sunroof, possibly blocked drains if you have? I use flexible net curtain rod to 'rod' through the sunroof drains on my Landrover.

No I dont have one

Found out the problem its where the lead for my taxi top sign enters the car