On April 21, 1967, the 100 millionth GM vehicle rolled off the line at the plant in Janesville -- a blue two-door Caprice.

There was a big ceremony, speeches. The lieutenant governor even showed up. Three days later, another car rolled off that same line. No one gave two craps about her. But they should have, because this 1967 Chevrolet Impala would turn out to be the most important car -- no, the most important object -- in pretty much the whole universe.

She was first owned by Sal Moriarty, an alcoholic with two ex-wives and three blocked arteries. On weekends, he'd drive around giving Bibles to the poor "gettin' folks right for Judgment Day." That's what he said. Sam and Dean don't know any of this, but if they did, I bet they'd smile.

After Sal died, she ended up at Rainbow Motors, a used-car lot in Lawrence, where a young marine bought her on impulse. That is, after a little advice from a friend. I guess that's where this story begins.

And here's where it ends.