Seems very simple and clean. You're saying Car UI - this meant to be a in-car system, and that is the front-end? If so, you might consider making it not only white icons on black background, but maybe give the user the ability to set chose between black/white and colored boxes (when looking at something for a short period of time, as you should do if driving a car, it's easier to distinguish a color than an icon/text).
Speeding up or removing the animations would be nice. The goofy animated garbage might look cool in a movie, or even the first time you see it, but long term in user interaction it's just going to piss people off. Waiting around with your thumb up your ass waiting for some goofy animation to finish is just going to make it feel pointlessly slow. Higher colour contrast would be nice too. Even zoomed in to double the size shown on that page it's very hard to clearly see anything -- but that's a common failing of using transparencies which is why that type of artsy bull ALSO is poor usability. A lot of that would probably hinge on the size display being used. If that's an in-dash 5" touch display, I'd suggest bumping up all the fonts on those icons, AND the icons themselves at least 50% in size. Likewise a thicker glyph font might be a good idea given the legibility issues common to thin-glyph fonts. (see why IMHO 99% of the goofy crap people are doing with webfonts right now is usability and accessibility rubbish!) It seems simple, and that's good -- sadly the usability shortcomings mated to the annoying long animations would make it very tiring to use long-term.
I agree with deathshadow, it's a great simple design but the animations would be annoying to those driving who just want a quick glance at the screen to perform an action. Although, for usability I would recommend colours with a greater contrast so that the icons stand out more, imagine scenarios with the sun shining in onto the device.