The chassis of the vehicle in my avatar is a 1991 EZ-GO Marathon injected-oil 2-stroke. The owner geared it down, and set the ignition so that it shuts off at idle instead of idling. It has a governor spring so you can adjust Wide Open Throttle so that if you accidentally step on the gas you don't go 30mph in reverse through your sleeping quarters *ahem*
We put about 7 gallons in it and gave rides, rescued bikes, took people to the deep playa etc in it several hours each day for the week. No idea how much the art weighs--say 200--but we had five people and a keg of root-beer on it.
Echo what others said: The playa eats small engines for lunch. Toward the end of the week we had to pull the air filter (our friend happened to bring an electric leaf blower. ...cuz...
), un-gunk the fuel filter and clean the spark plug, all of which only took about half an hour.
DMV was easy but it was pretty radically mutated. We brought our wing-walkers to the DMV so they knew it was intended for more than just hauling our lazy asses around the playa. The idea isn't to do the minimum get a license, the idea is to make art that lends itself to the awesomeness of Black Rock City, and happens to be capable of hauling your lazy asses around the playa.