Car is 1995 GF8 WRX import

I need advice locating the source of a leak and I've just read through all the boot leak related threads with no luck. I've narrowed it down and it isn't coming from the light cluster seal but instead above the light cluster, I think it's most likely the roof rails since I poured water onto the rails and the water pooled a bit more. Has anyone had any expereience with this kind of leak and know a surefire way to fix this leak? Are the rubber cushions what prevent water ingress or are there rubber seals underneath the rail and bolts? A few pics underneath for an idea of what i'm on about


Sourceish of the leak inside the panel above the light cluster


light cluster for reference

Perished roof rail cushions