The people of Bristol are inadvertently powering a VW Beetle convertible using their own - and there's no delicate way if putting this - faeces.
The prototype has been developed by GENeco - the green arm of Wessex Water - and is called the Bio-Bug.
Actually, the car runs on methane stored under pressure. That, in other words, is merely compressed natural gas (CNG). But while CNG is a much cleaner fuel than conventional petrol, it is still generally a fossil fuel.
This is where Bio-Bug is different, because the methane is produced from human waste at an Avonmouth sewage plant.
The Bio-Bug's converted 2.0-litre motor can still take it to around 115mph flat out, so while it doesn't exactly go like you-know-what off a shovel, the (ahem)
Beetle can still hack along at a fair rate.
"Previously the gas hasn't been clean enough to fuel motor vehicles without it affecting performance," says Mohammed Saddiq, GENeco's general manager, but Wessex Water have imported specialist equipment to treat the biogas so that the Bio-Bug - built by an outfit called The Greenfuel company - can run untroubled.
"Our site at Avonmouth has been producing biogas for many years which we use to generate electricity to power the site and export to the National Grid," says Mohammed. "With the surplus gas we had available we wanted to put it to good use in a sustainable and efficient way."
GENeco says that the - er - wind-powered VW can run for 10,000 miles on the annual output of 70 household porcelain thrones.
All of which is very nice (Is it? Really?? - Ed), but it wouldn't give prospective Bio-Bug owners much defence from those who contend that the 'New Beetle' is a pile of sh*t. Because GENeco has rather proved that it is just that...