Thus we don't have more.
However if you can get your hands on or build a device to raise that 12VDC steady on to about 100 volts pulse the output will run on tap water, swamp water (after filtering through some cheese cloth and sand, or even manmade water.
These plans are also available on the internet. Some free and some for cash. Either way it will keep the lights on and the ford chugging, if not zooming, down the road.
The plans I saw put it all in a 4" Black PVC pipe. They use two stainless steel pipes one about .53" smaller than the other for the plates. Mount them insulated inside each other. This gives you more plate surface. Then by using a simple high voltage multivibrator (switches the voltage as it is amplified) circuit mounted under the dash.
Guy in town back two years ago when the gas was very high used a stainless steel pressure cooker with two simple electrodes to run his dump truck.
Not neat, but better than walking.