I like that the fuel gauge is black now, and the fact that the rear fog light cover now serves some function is nice.
Not too sure on the front bumper. The LED's look out of place, but at least there are lines on the bumper that kinda flow with them. I'm disappointed that Nissan didn't integrate DRL's into the headlight housings though. I find that look a lot better than having random lights popping out of the bumper.
Also, never thought I'd say this, but the new bumper makes me realize how much personality the fangs added to the car. Even though the 2013's shape is a little more aggressive, with the 350z style grille, it also manages to look blander than 09-12 Z's.
BTW, The new wheels now look a lot more like an extra swirly version of the lexus IS250's wheels
