headlight upgrade

[Major Rant]

OK as an additional light but as a main source of illumination they are highly illegal,

:agree 
The real reason that LEDs aren't installed as main light source in mainstream automobiles is that they have problems at the low and high ends off their temperature range.
At -40C they are too bright - now that could be controlled but it would be expensive.
At +125C it is impossible to drive them hard enough to generate enough light without them getting too hot. That could be solved with a refrigerator - again expensive.
So they are 'uncertifiable' for Automotive 'main light' applications.

They did however issue a 'special dispensation' for the Audi R8.

Frankly in the UK you could use them but just don't expect them to work on a hot day in Arizona during a total Eclipse.