Was "Black Cadillac" based on a true story?

In the movie Black Cadillac (made in 2001/2002 directed by John Murlowski) a group of high school kids go on a roadtrip from Minnesota to Wisconsin, and are terrorised by a savage Caddy driver a la S.Spielberg’s Duel.

Now at the beggining of the movie we are told that this is based on a true story. Somehow, I have a difficult time believing that there was some (seemingly) omniscient Caddy driver who was hunting down a group of schoolboys for kicks. I mean, the way they show it in the movie, there’s just no way that some dude could have plotted all that in the space of time the movie alludes to. And you’d assume that if it was a true story then it couldn’t realistically have been over more than one whole day that all these events occured.

So what’s the deal here? Just how true a story is it?

What exactly is it based on?

Knew I could come up with a Q nobody could answer.