Methane powered car runs on human excrement
5 August 2010 Last updated at 15:27 BST
A VW Beetle car that runs on methane, generated from human excrement, has been developed in an attempt to encourage sustainable motoring.
The BBC's John Maguire has been to the Avonmouth sewage treatment plant near Bristol, to see the car, and learn about the process for powering it.
Mohammed Saddiq, of sustainable energy firm GENeco who developed the vehicle, talked to him about the car's benefits.