registrations for those who did not pre-register do exist for people seeking disabled licenses who have a valid disabled drivers license plate or placard.... they can just show up at the DMV during operating hours
as for someone who was recently injured and may not have that, my guess is that it's likely to be some kind of case by case basis thing and may require some kind of "proof" ..i.e. paperwork and for more info... that would be a question for the dmv...... email them! dmv [at] burningman.com
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