Rear window leak

I have a 2008 double cab and iv noiticed for awhile that I have a water line down the drivers side of the back glass and today It rain and I felt it and it was wet so any ideas on how to fix should I pull the headliner or could it be there third brake light

 

It could be either the Third Brake Light, The Glass in the frame or the seal between the frame and the body.

 

Bump

 

I found where it's coming from not the third brake light it's the window seal now to take the headliner down

 

Mine just started leaking too (175K miles). It is leaking from the top of the two outboard rear windows, wetting the headliner and dripping onto the rear seats. It seem to line up with where the rooftop rain gutters come into the rear window seal. Has anyone else seen this? Or has anyone pulled out the windows or gutter pieces and can give some guideance?

 

That is right where mine was leaking I pulled down my headliner and could see a gamp in the sealent just added some and no more problems