For headlights, using the projector plugin will give the best effect. Check out this code and the attached .jpg
Code:
import viz
viz.go()
model = viz.add('tankmaze.wrl')
import projector
left = projector.add(viz.add('spotlight.bmp'))
left.border(0.3,0.3,0.3)
left.translate(-1,1.8,0)
left.affect(model)
right = projector.add(viz.add('spotlight.bmp'))
right.border(0.3,0.3,0.3)
right.translate(1,1.8,0)
right.affect(model,2)
viz.link(viz.MainView, left)
viz.link(viz.MainView, right)