First, what a great marketing angle, a self-cleaning car, how cool is that! I imagine 6 o'clock news stations across the country showing clips from this video tonight.
Second, what a great up-sell opportunity. Now every oil change service done by Nissan can include a new $50 charge (or whatever the market will bear) for re-applying the self-cleaning paint.
Third, could they even push an environmental angle? Ie. litres/gallons of water saved by not going through a car wash?
So, with one new feature Nissan has gained free marketing, and an incremental revenue source for their dealers. Not bad for a mature market.