Honda has been working with FuelMaker Corporation to mass-market a system that connects to a home's natural gas supply line to allow owners of natural gas vehicles to fuel up at home. The CNG-powered Honda Civic GX will go on sale in California in Spring 2005, according to the automaker.The system taps into the household’s natural gas supply, compressing the gas to the much higher pressure needed to run the car. FuelMaker's pump, called Phill, is about the size of a pay phone and can be installed in a garage or outdoors. Drivers would leave the pump in the car overnight and have a full tank that could take them up to 220 miles in the morning.The Phill system retails for about $2,000. The company hopes eventually to mass-produce 20,000 to 40,000 units, which would lower the cost to $1,000 each.