Or as above, but dump your supplies and one of you at one of the rideshare locations in Reno. Return the rental, go back to the Rideshare location. If you're flying into Reno, and getting the rental at the airport, consider using the Rideshare at the airport?
p.s. I see that along with Air Playa Info at the airport, they're listing one Rideshare base this year: the Keystone Save Mart location. http://www.burningman.com/preparation/t ... rport.html