To be honest Dave, I'm not certain. I'm sure I have seen them on websites
where they claim to match the specs for brightness etc, so I've always
assumed that any that are deliberately manufactured as 'replacements',
would similarly match. However, I accept what you say, and they might not
all be. Are the likes of Lucas or Delco or whoever making these things yet
? I guess that would be the best guarantee of compliance. In any event, I
should think that ones made for the job, are likely to be better in terms
of brightness and viewing angle, than something that you would cobble
together yourself ??



There are many retrofit lamps on the market which are certainly *not* street
legal, and for obvious reason if you see them in action. I don't know if
anyone makes any that are, but I would think the technology at least exists.

I don't think there'd be a problem using retrofit lamps for things like
license plate illumination and certainly anything inside the car, but I
would hesitate to put one in any of the external marker or signal lights.