I Can Barely Remember to Signal

Linked above is a New York Times article about an "emotional" car invented by four Toyota employees.  The car, through designs to its appearance, would be able to "show" emotion. It would have varying colors of light through the headlights, as well as eyebrows and eyelids. It would even be able to lower itself and turn red, as though growling in anger.

This seems like an interesting idea, but not necessarily something I would want my car to do. Isn't it too much perceptible emotion that makes driving a bit intimidating?  I'm afraid enough that someone is going to give me the finger for driving poorly -- there's no telling what I would do if someone's Celica began running me down.

From my reading of the article, it seems as though the emotions are not operator-controlled. For example, I couldn't flip the emotion switch to "delighted" the way I switch the blower switch to "defrost." Rather, the car builds up "points" based on stimuli that come from driving. I can see how fast starts, stops, and turns, could make the car develop angry points, but what are the stimuli to make it happy? The car can't know if another car is yielding. Or if . . . or is that the only nice thing someone else in a car can do for you from within their own space? Maybe that's the problem. Perhaps we don't have enough nice ways for our cars to interact. I'm sure there's a lesson for us in there.