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.
Using GPS on a phone while driving is illegal as well (in CA): http://www.dmv.org/articles/california-bans-use-of-cell-phon...