As far as we know, Doc Brown's DeLorean was the first car to be nuclear powered (and before you comment, we know it was just the Flux Capacitor that ran on plutonium). But then he never got to the Moon.
The Chinese are planning on sending an orbiter named Chang'e-1 up there this year in preparation for a landing in 2012, eight years before the US plan to send men back to pick up Alan Shepard's golf balls.
The plan is to make this "better than the early US and Russian rovers". With an average speed of 100m or 328 ft per hour it won't be breaking any speed records. The real concern is safety. Other countries have consistently backed away from sending anything nuclear into space because of the obvious dangers in case of a crash. That said, the American rover runs on lithium-ion batteries, and we all know just how fond they are of the odd explosion.
