|Just in case I forget what car I have at night!|
You will need a spec 1 clear rear panel, LED strips, red translucent paint (tamiya clear red will do), masking tape, hot glue gun, some thin plastic card.
1. cut a window either side of the central lug to the end lug on the back of the panel.
2. spray the interior with red translucent paint. You will need a couple of coats to get this a nice dark shade.
3. motor factors now sell LED strips for front light fittings c/w wiring, they also have an adhesive strip on the back. They are just the right size too. It is a little fiddly but stick one top and bottom.
4. you don't have to but it is a good finish. Cut out of your plastic card two rectangles to cover the holes you cut previously, glue with black hot glue. Spray the back or the panel with satin black.
5. mask the external lettering of 'SKYLINE' then prime and paint.
6. Fit panel and wire into your main rear lights with a connector.
Things to check. Make sure that you do not have any old silver paint on the skyline lettering. When masking use a scalpel to cute the tape, trimming around the top's of the lettering and not the base.
Do test the lights before you seal everything up, they will run off any 12 V source well enough.
Make sure that the red you paint internally is dark enough, use four coats at least (dependant on thinners).
Do remember in the UK you can only have red illumination on the rear of your car!
Going off piste? There are now red LED's available. This may make the job 100% simpler. I have never spoken to anyone else about how they did theirs, although cold cathode tubes look crap!