Only art cars and bicycles are permitted to drive around at Burning Man.  Art cars may be small or the size of flat bed trucks.  You might see a living room drive by, a multi-tiered moving party complete with a bar, a fire breathing monster or a band.  I wish I had some shots of Dr. Megavolt for you.  A truck with a couple of 6+-foot tall Tesla coils, and a man in a metal suit dramatically drawing lightning arcs from them to his hands.

(Click on the thumbnails for a larger image.)
 
Many of the art vehicles at Burning Man are simply fancy ways of getting around.  The Death Guild/Thunderdome crew has a whole fleet of vehicles rebuilt to look like they're out of the Road Warrior.
More often than not, fire is involved.  These little guys had flamethrowers in them.
Many offer rides to those who want them.  Like this one, a magic carpet complete with a hookah.  (This image also demonstrates why night shots are tricky out in the Black Rock desert -- there is so much dust in the air that and flash lights up 'snow' and generally ruins the shot.)
Or these miniature trains...
But I'm holding back.  The really memorable stuff is more distinctive.  Meet Draka, a fire-breathing creation as long as two buses.
  Or an entire galleon, from 2002, when there was a water theme.  There was space for a band to play on the back.  
  I needed Straylight's help identifying this one.  No, it's not the Cheshire Cat.  It's the Catbus from 'My Neighbor Totoro,' an anime film from Japanese director Miyazaki (creator of Princess Mononoke).  
This shot shows a bus-sized shark in the distance.  Off to the right of the scene is a circle of large fans that could set up a big fire vortex when the air was calm.
  I wish I'd seen this one in action, there were three seats around the center hub with pedals by each.  If it actually works, each person would have foun themselves lifted high during part of the rotation.  
  It's cute, sometimes I'm a big softie.  So sue me.  
  Arrrr...  
  This vehicle was preceded by people with large butterfly nets who would trap anyone dressed as an animal and toss them in back.  A man with a megaphone lectured how it was for their own good.  Protesters with signs ran up at one point.  It was all amusingly chaotic.  
  Not as dressed up as art cars should be, but the idea of driving around offering merry-go-round rides is worthy of mention.