Mark does the light still shine through
...first time seeing those too..
My 3rd brake light is disabled due to the fact that I have one on my TRD
spoiler, so I couldn't tell ya.
But, I do have the overlays that go on top of the rear brake lights, and I know for a fact that light does NOT shine through, so I don't see why it would be any different for the 3rd brake light.
But if you don't want it to shine through for sure, you can always just pull the plug on the brake light by opening the hatch and pulling out a rubber grommet that will then lead you to the connection.
EDIT: But I do believe that it is illegal to disable your 3rd brake light without having one somewhere else, like on a spoiler or something.