That's not really accurate. The first time the CMU vehicle went several miles before getting stuck on a rock or something and then spinning it's tires until they caught on fire. They spent the next year improving that vehicle, and developing another. I don't know the specifics of the course changes, but many friends of mine worked on CMU vehicles, and I can tell you they definitely improved things (like activating a bunch of sensor systems that they didn't use in 2004 because they didn't have time to test them before the race) for the 2005 race.