On the MX-5 NA and Eunos Roadster, the high-level brake light sits inside the boot lid and shines through a rounded, rectangular hole. It is lit by a single 12V filament bulb, which doesn't provide very even illumination or a fast response time when compared to LEDs.
The light unit comes in three main parts: the red plastic lens, the grey case with integrated mounting points and a foam seal (removed in this photo) that stops water getting into the boot. The two plastic parts simply clip together and it is very easy to separate them.
You can buy clear plastic or tinted plastic LED versions but these are typically around £60 or more. We don't want to change the exterior colour of this light as it is already a dark red and this works well against the black paintwork planned for our MX-5e. Replacing the whole unit seems overkill, when all we want to do is improve the light output.
Our plan is to simply fix a 3D printed bracket with some ultra-bright LEDs, so that we get much brighter and more even illumination.
Our chosen design uses three 'eagle eye' 12V LED lights that mount to our 3D printed bracket. These fit nicely within the housing and can be simply wired up to the existing wiring. We are using 6.3mm insulated spade connectors to enable the lamp module to be removed.
This is the completed module ready to be installed.
This is what the module looks like installed and off. It is very bright when on.