That article is specifically about using your phone as a GPS while it's in your hand. Using it hands-free in a car dock is a different matter (and much closer to the Glass scenario). From the article you linked:

  Had Spriggs’s cell phone been fastened on a dash dock, the
  story might have turned out differently; that’s because,
  even though California has a hand-held ban for texting,
  talking, listening (and now, using GPS), it doesn’t
  prohibit hands-free cell phone use.