i went looking for a light for my cigarette lighter ring (they're the same
size) at the local VW dealership.  when i ask the guy if he had any, and how
much they cost, he just went into the back and came out with a entire
cigarette lighter unit (which includes the light and light housing), minus
the removable doohicky that you use to actually light the cigarette with.
he said that they have to order them all the time to replace the doohicky
that people have lost, but since it only comes as a full kit, they end up
with a couple of the dashboard portions of the unit sitting in their bags on
the shelf.  he gave me the whole unit (minus the aforementioned doohicky) in
the bag for free, since it didn't have a part number as anything other than
a full unit.  it's worth a try.
jason