The Smart car of the future. Scientists are currently working on a way to contain human flatulence for use in smaller, more efficient vehicles. The prototype tested has only been able to travel a few feet due to limited amounts of flatulence available per person, but the experts are also working on a way to clone and condense human farts so that one fart can become many more, thus increasing the volume available per person. People will be encouraged to consume large amounts of fiber (especially Fiber Bars) and carbonated water and drinks to increase their gas production. Instead of plugging your car into an outlet and wasting electricity, or buying the more traditional, expensive type of gas, you would fart directly into a tube that leads into your car's "gas tank", which will have a self-sealing valve after each deposit.
The Fart Car will prove to be a valuable means of transportation in the future, as farts are free and we will no longer be required to depend on foreign oil resources. The future is looking brighter, if not a bit stinkier.
"I can't wait to buy my first Fart Car!"