Model Railroading > The smallest LEDs?

In browsing around for pre-wired surface mount LEDs I came across a couple of vendors now offering "Z" or 0201 size.
The voltages are the same for the same colors of larger size, about 2 volts for red and 3.1 for white.  But they are happy with much lower current ratings.
My tail lights are running on about 0.5 milliamps and the next ones I do will be even a little less; they are bright.
Jim Hinds, of Richmond Controls, advises that they will fit inside a 0.030" hole.
So far I have only used a pair of red for tail lights on a highway vehicle but can see them in several other places.
One of the web sale sites advises that they may not produce sufficient light to light up a room (as in model buildings?) but I think they can do headlights just fine.
Has anyone else used them?

Please elaborate on "pre-wired surface mount..."  That seems contradictory to me.  Are they on a little board?  Pig tails directly on the surface mount devices?  Other?

Thanks

sf1010 Wrote:
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> Please elaborate on "pre-wired surface mount..." 
> That seems contradictory to me.  Are they on a
> little board?  Pig tails directly on the surface
> mount devices?  Other?
>
> Thanks

Search SMD leds.

Evans products has illustrations on their web site, and countless vendors will show you examples if you go to Google or that on line auction site.
Basically you pay a little money to have machines make the very delicate solder connections to each end of the SMD.
They have been around for decades, it is the type Athearn uses in their LED equipped locos.
 

do you have a link? i could use a couple of red/green micro leds