Water leaking into the boot thought it was the light but it's not any ideas?

[titch]

I was convinced it was the light as every time i took the inside cover off it was wet, but watching it today i could see the water getting in at the top and dripping in behind that cover, and i have fitted a brand new light.
Eventually when the rain stops, i will whip off all the plastic trim on that side and try and find where it is getting in.
Might chuck a new boot seal on, just wonder if any of the seams on that side are leaking.

Its not to bad at the moment, as i have a plastic boot liner / tray in there so all the water drips into that all the carpet and underlay underneath are still dry.