Why let human waste go to waste? This modified Volkswagen Beetle “has been converted to run on the biogas produced by the Wessex Water sewage plant in Avonmouth, Bristol.” Unfortunately (or fortunately), there are no plans for mass production…yet. Video after the break.
The only modification is hidden from view, in the boot, which has been sacrificed to fit in two large cylinders of methane. The car still has a fuel tank, and a very small amount of petrol is used to start the engine, but the car switches to biogas after a matter of seconds, rather than minutes.