You can retrofit a projector into your housing if you're concerned about glare, but it is possible to remove the lens and pait over those reflectors that are responsible for the glare spots. I've seen it done before.
If you want to learn more about all kinds of clever lighting projects, you might check out the HIDplanet forums. Not only are people retrofitting all manner of projectors into their cars, you are likely to find information on replacing tail/brake lights with LEDs; and not just cheap LED bulbs from the automotive aisle.
The simplest solution I can think of for a rallyist concerned about glare on transits would be to keep regular bulbs in the car, but consider an HID upgrade to those lights in the pods after dark. They're only on when you really need them, right?
Brian Driggs | KG7KCA | PHX, AZ | 89 Pajero
alterius non sit qui suus esse potest