I really don't think they car about your dirt modified, stock car or late model. They are mostly talking about 3/4 , 1 ton, and semi trucks. and that they don't want someone removing the emission control device on a "certified vehicle" just for a competition. IMO They are just making it easier for them to regulate someone buying a Chevy Corvette and buying parts "for competition" and driving the car on the road illegally.