Is the rule really about "track use" or is it just off-road or on-private-property use? How does the distributor know I'm not just rolling coal on my uncle's farm?
From what I can find, "track use" isn't in the law, but rather a matter of enforcement discretion.
"The Clean Air Act does not contemplate removing emissions controls from an EPA-certified motor vehicle in order to convert it into a competition vehicle. As a matter of enforcement discretion, the EPA’s longstanding practice has been not to take enforcement action against vehicle owners for removing or defeating the emission controls of their EPA-certified motor vehicles, so long as they can show the vehicles are used solely for competition events and no longer driven on public roads."