Portland has "food truck pods" on the edges of downtown parking lots, as well as in parking lots throughout the city. They have an incredible diversity of cheap food, and the businesses are obviously low-overhead (often in trailers instead of trucks) and generally seem to be staffed by their proprietors. Here's a random blog post with pictures: http://blog.chowmenow.com/join-the-pod-y/ It seems like a great way for a city to take an ugly downtown parking lot and make it a pedestrian draw.

New York City doesn't really have surface parking lots anywhere with a lot of foot traffic, so that isn't really an applicable solution here.