Just talked to my friendly Michigan MV officer today and I explored the question with him. We used the race car example and he pointed out that even winning a trophy could be considered "for profit" if the stopping officer was having a particularly bad day. He also pointed out that a lot of places are cracking down on the car's fuel. 8 gallon limit in a jug before a placard is required. Not much fuel for a night of racing. I want to haul some of my company tools (machine shop) in the trailer while on the road and he said that I would likely be pinched if caught. Still contemplating the route that I'm going to take.
Bo