The first link discusses how they did it.
It took 606 takes.
The second link is the video. None of it is computer generated or faked. Even the tires that roll uphill. (The tires were weighted inside just past 12 o'clock.)
http://www.telegraph.co.uk/news/mai.../13/ixhome.html
http://www.boardsmag.com/screeningroom/commercials/581