Crown Vic's, Camry's and Civics have been produced as factory dedicated CNG cars, so parts were made for those. Only the Civic is in current production. My brother just bought his second CNG Civic. The fuel is $2 an equivalent gallon in Los Angeles, but that is because of a monopoly on public refuel stations. The added bonus is that he is allowed solo in carpool lanes. New hybrids no longer qualify.

Jim