I don't know about other owners, but I have noticed that with the small side mirrors that I rely on the back window to see what's going on behind me, & between the stock 3rd brake light and spare tire takes up a lot of the rear window view, so to get a little better view I replaced the stock 3rd brake light with a smaller unit, that I made & it helps you see more out the back window, it only takes up 1" as compaired to the stock 3".  I made some brackets to hold the light & mount into the stock holes, so no drilling just cut the wires & replace the electrical plug.
  I find that there is real improvement in what I see now. and there is more light for those tail gaters to see, so I think it makes driving safer
Let me know what you think

That is alot nicer looking than the stock setup.

I took my third brake light out years ago, because I wanted to see better.  Where did you get this light?  I had thought of doing something like you did, but I never found a replacement.

The light is out of a 96-99 VW Jetta It's the one that mounts on the glass at the top, make sure that you get the elect. plug & the silver mounting brackets that are stucked to the glass the light snaps onto these, then just cut off the plastic angle that matches the angle of the glass, right in front of the lens leaving just the light.  I then took some sheet metal & made some mounting brackets to use the stock mounting holes, then used some 3M double stick tape to mount the silver brackets to the sheet metal brackets... splice in the plug there is no + or - on the wiring so just splice it in.