one way to solve the backup lighting problem, without the
possibility of melting anything in your taillights, is to
put a clear fog light on the rear bumper. :) wire it in,
using a relay for power switching, to a switch on the dash
(that way, you don't have to burn the fog light during
daylight backups). works wonderful ... especially in the
woods!! you can actually see at night.

the downside? :( cost ... fog lights usually are sold in
pairs, and aren't cheap. it's also a looooooong way from the
rear bumper to the front/dash of the bus. but after it's
done, i think you'd agree it's worth it.

one caution. don't get frisky with the size of the fog
light: anything big is gonna impact the closing of the rear
hatch ... so a rectangular fog light would probably be best.
i mounted mine on the passenger side, and angled it a big
toward the driver's side.

joel