Evolution of white LEDs
The images show how an idea for LED interior lights evolved.

LED evolution sequence

The yellow tint of the original standard filament bulbs really wasn't appealing. Well, if it was that easy it wouldn't be any fun!

Initially, commercial T10 LED bulbs were fitted, but most of the light was directed forwards into the headlining and door cards. This seemed a little wasteful, so foil reflectors were mounted in the fittings to direct the light where it was needed.

However, as the identical LED sidelight bulbs began to fail, they were replaced with newer bulbs borrowed from the interior. The faulty bulbs were repaired with new UK specification LEDs mounted so that the light was directed from the side of the bulb, better for the interior lights.

It all seemed much easier to simply design an LED bulb that both worked reliably, and directed light from the side. So we did. Obviously there is also a variation that can be used as a reliable sidelight bulb, too.

The moral of the tale is that if you can't buy it, build it….