Wow. Who knew that other people's crap will get you far in life? 

A Bio-Car..... wow..... Let's load up a truckload of fatties then feed em Exlax. That'll get you good mileage. 

The Future competitor to Hydrogen powered fuel.... Septic Gas Stations.

How exactly will this help combat "global warming"?

Perhaps my understanding of these things is deficient, but do burning farts not produce CO2, too?

It's not the half of the planet that has no toilet to pee in that is responsible for global warming.
It's the 1/6th of the world consuming 9/10ths of world resources that is responsible for global warming - if anyone is, that is.
So it sounds kind of ironic, if not downright cruel, to ask the part who have the least to do with the problem to take part in solving it.
On the other hand, it's a great idea. Now, could we have a livestock version to take care of all that cow methane ?

The reason it helps to combat global warming is that the methane burnt from 'farts' is carbon neutral. 
In the case of a cow it comes from the digestion of grass and it's subsequent bio-degradation by microbial action.

A recycling bog? That recycles faeces?

That's nothing new. Most of the bogs on t'intermawebnet recycle verbal diarrhoea alrea... wait, an *actual* bog?

My mistake, move along, nothing to see here...

This is already a reality in Sweden!
I drive a bio-gas driven car that runs on methane CH4, thats extracted from ppl´s s*********, garbage or other things!