020 Hybrid Taxis
The only vehicles that should be aimlessly cruising the streets should be hybrids, or better yet, electric. Quiet, clean, efficient and just a little bit underpowered to keep them traveling at sane speeds, the new Taxis should be the most advanced cars in The City.
California sets the nation's standard (and the world's) by demanding that automobiles sold there meet their needs. The same could be true for The City's taxi fleet: what we demand here will ripple through all cities. We might even become the testing ground for every new idea a car company might have.
As long as they are yellow.