What's this, another official VW game? Well, yes, but it's quite different from the Touareg and Scirocco apps. Instead of a 3rd-person view racer, the up! Challenge is more like the old Micro Machines game, with a top-down view.
You'll be racing the new up! across different circuits set in a utopia-style city, albeit one of Volkswagen's vision, where everything is white and blue. There's actually quite a good sense of speed and the cars are easy to control with your right thumb handling gas and brakes, and your left thumb commanding the steering.
There's quite a cool vibe to the game which suits the iPhone's style and it should be easy to pick up even for those who don't consider themselves gearheads. And once again - it's free.