Another Nascar movie... true or false?

Rating: 5/10 (25 December 2006)

I actually haven't had the opportunity to see this movie yet, but I had one big question about the movie...
Is this based on a real-life story or just complete fiction???
I just saw Farrell and Reilly on Larry King Live this morning, AS Ricky and Cal. Larry didn't ONCE call them by their REAL names, only as the character names. And they were taking calls and talking to other NASCAR drivers, such as Richard Petty. And now they are talking to the guys about "making a sequel to their movie, and having actors play them instead!" LOL He said Will Farrell will play him. This is the funniest Larry King Live I have ever watched!!!
So I am confused... were the main characters real or made-up? Can somebody PLEASE explain if this is a real story???