Hi N6JMX,
Thanks for getting back to me, there was a small amount of water in the boot when I got the car but over the last few days it has filled up considerably about and inch worth of water in the wheel well.
The smoke machine is a good shout, never thought of that, I knew there was a reason for having one 😆
I have heard that the boot seals can get dirt underneath them which creates a wicking effect and can lead to water ingress although having pulled the seal back there’s evidence of previous silicone which would suggest a different issue.
I think I’ll remove the seal and soak it in the bath, and refit it with some silicone sealant after treating the rust that’s forming on the pinch welds and see if that makes any difference.
Cameron