Cabriolet third brake light

Does anyone know of a way of adding a third brake light to a cabriolet? I have seen pictures of American models with a light cut into the bodywork above the rear number plate but I dont want to "cut up" my car (even if I could locate the parts).
I could stick a strip LED light to the window but that would
i. Get in the way when the roof was down or cause the roof to not lock down properly.
ii. Not be visible when the roof was down.

Ideally I want a strip of red LEDs that could be stuck onto the tailgate above the lock with a small hole drilled into the tailgate to take the wire down to one of the rear light clusters. The light manufacture RING make indicators that are that are 22 yellow LEDs mounted on a flexible, self-adhesive strip. These are for sticking onto wing mirrors to give a Merc look. Search Demon Tweeks web site for "M-Lite" to see a picture.  The problem with the M-Lite is that the LEDs are yellow. Sticking them behind red plastic or spraying them red would look wrong and not please the MOT man. Surely I am not the only one that does not want to get shunted because the other driver didn?t see my brake lights?

Managed to get a third brake light from MG/Rover. They do an LED strip for the mk1 MGfs (R plate). Job done.