Eric wrote:
What's the deal with these?
http://www.weirdstuffwemake.com/automotive/vanagon/pics/misc/NewBusTailLights.jpg
  What/where did you get these?

Eric, you make them --- by cutting a hole in the dummy/blank spot in back of the taillight lens, then on the taillight bulb housing, run a jumper to the dummy/blank spot to power the bulb-fabricate a steel jumper in the bulb socket to touch the bottom of bulb (works best if you can scavenge a salvage housing for the steel jumper) power from either brake or running light.  This gives voltage to the bulb, ground is already present.  Enabling switched operation becomes tougher since you will need to run wire to the taillight to actually switch the bulb, the housing helps somewhat by providing current paths via steel flats affixed to bulb housing and a vacancy on the wiring harness plug.  Once you get in there, you will see what I mean.

Good luck.

JB -updated taillights on 3 vans so far....