Not What Doc Brown Had In Mind 

It seems a German inventor has come up with a new way to power cars using paper, rubbish, plastic, and dead cats?:

Christian Koch, an inventor and patent holder of the "KDV 500" that he said produces high quality fuel, said he can transform waste products such as paper, rubbish and plastic materials into fuel.

But Koch, 55, said there was no truth to stories published in Bild newspaper on Tuesday and Wednesday that suggested he used dead cats as part of the mix for his organic diesel fuel.
...
Bild on Tuesday wrote a headline: "German inventor can turn cats into fuel -- for a tank he needs 20 cats." The paper on Wednesday followed up with a story entitled: "Can you really make fuel out of cats?"

A spokesman for Bild told Reuters the story was meant to show that cat remains could "in theory" be used to make fuel with Koch's patented method.

Actually I don't see the real issue here. People bury their cats, or cremate them after they die... what is so horrible with using an already dead cat to power your car? It's not exactly sentimental (I sure as hell wouldn't), but who said you have to be? On a side note, the first thing that came to mind when I heard about this invention was Mr. Fusion from Back to the Future Part II.