So I just went wingless and got a 3rd brake light from local dealer. Searched all forums, nasioc, scoobymod, i-club, and here. But can't find instructions on installing it. I know it's easy to install, but I want to know where to cut the hole, so the light is centered. Can anyone direct me to a link or forum?

Oh btw installing on '05 WRX.

Thanks.