Well, after building some tiny NYC landmarks, I decided to make some tiny cars to go with them. They're all about 2x4 studs.  I made models of some of the minifig-scale cars I have in my city.  Namely: taxicabs, a police car, a bus, an SUV, a cargo van, a 1962 VW Microbus, and a limo.  I'm really having fun with this, so you'll probably see a lot more "mini" from me in the future :)

Taxi cabs! Also check out my normal scale and very large scale taxi cabs.

A New York City Metro Transit Authority express bus, designed after a classic 3-axle MCI bus.

A cargo van, like a Ford Econoline, with PVC piping and a ladder on the roof.