You've all got it wrong.
I can't remember the name of the movie, but it was about these competing wrecker services. So in order to get business one of the companies carried the magnetic door signs of all the wrecker companies in town. So they monitored the police and business band for calls and sniped everyone else's calls. I'm sure that's how they do it up there!
BTW, wreckers are supposed to be on a rotation. But certain companies have peeved certain officers and troopers. SO often those companies get skipped.
So when I see a wrecker speeding down the highway I usually don't think much about it because I remember they have limited time to get to the scene.