The first layer protects from sun and repels water, the second layer features "nano-dust" to push dirt to the edges of the windshield and is activated by the third layer which senses the dirt, while the whole kit is powered by the fourth layer which conducts electricity to keep it going. The tech could be ready for mass production within 5 years, but there's already a working prototype in the Hidra concept car.

Wiperless windshields in your future? Thanks, nanotech.