You might not know it, but the Honda Civic GX is immensely popular these days. You couldn't get one of these compressed natural gas-powered cars is you wanted one, according to Green Car Advisor over at Edmonds. The best you could do is put their name on a waiting list that currently will get you a GX around June (only Honda dealers in California and New York sell the Civic GX to normal customers).
Edmonds write that Honda is thinking about doubling the number of GXs it makes each year (currently 1,000) and that for most of the past decade, Honda sold around 700 of these cars each year. GX buyers make some sacrifices when they opt for the GX over the base (and gasoline-powered) LX - less power and a higher MSRP - but demand for the gasoline-free cars is still shooting up thanks mostly to the cheap cost of natural gas. The carpool sticker offer probably helps driver sales as well, but Honda'll take our money whatever the reason.
Related Gallery2007 Honda Civic GX
Green Car Advisor]