2008 Sport
So, I've noticed water soaking in the spare wheel well for awhile now, sometimes the back trunk floor is a bit wet. BUT, since I never drive it in the rain (wife does, it's her daily), I never could figure out what the heck is going on.
Today, I get the Fit, it's pouuuuuring. I open the back to throw stuff in, and see a pool of water. I drive home, and notice water leaking on the window on the INSIDE, and water dripping off the 3rd brake light.

So, pics be here over all and here Blurry, but can see the wire. Can't see the hole though of where I think it's coming in.
The wiring for the light is coming through a hole that is in the hatch frame. I can't find ANYTHING else that would allow water in. Gaskets are dry on the inside. Brake light is wet on the INSIDE.

I haven't taken off the rear spoiler to see if there is water access there......does anyone know if there is? Should I just plug the hole with silicone, or take off the spoiler to make sure if there is water entrance in the gap between the plastic spoiler and the actual hatch frame? (I'm guessing pop off the plastic covers and there is some sort of bolt under them?)

 

The GD water leak has been discussed numerous times here but I don't recall anyone having a problem with the third brake light being the culprit. Then again, I wasn't reading all the threads I just lightly skimmed over them. Try reading what other membera have done and see if that yields any new insight. Worst case scenario: you could always take it to a dealership and see what they say. Good luck!