These guys claim to have created the first autonomous motorcycle robot. 8-)
http://www.ghostriderrobot.com/videos.htm (http://www.ghostriderrobot.com/videos.htm)
Rather interesting, though I will say it does not appear particularly skilled at driving.
Along the lines of motorvehicles turned into robots, has anyone seen the remote-controlled Toyota? It was not autonomous and certainly no monumental technological achievement, I thought it had a more interesting video. :-D
http://www.digichapman.com/images/rccar.wmv (http://www.digichapman.com/images/rccar.wmv)