Isn't the the problem dirt particles other than dust from the cheese grater type tires used to achieve maximum traction the problem? Tire technology has evolved a lot faster than dirt tachnology. It also seems a less tacky track also helps keep the cars shiney side up with less grip and more slip. Maybe there's a university than can develope a synthetic clay for dirt tracks. Don't laugh, we have safer barriers with help from the University of Nebraska. Just a fans observation over the years.