I don't understand the infrastructure problem with natural gas? Almost any town of size has natural gas piped to homes. Why would it be difficult for gas stations in almost every town to sell it at the pump and for people to be able to refill at home if they had natural gas service at home and wanted to buy the compressor? Of course I know very little about using NG as an automotive fuel.
In the late 70's the father of a friend of mine had a NG truck that used both gasoline and NG. If you ran out of one fuel you switched to the other. You can have kits installed today. The biggest problem is that it takes a good sized fuel tank.
Honda has a NG only Civic and North Little Rock has a public NG station.