Looks like the EPA is considering further regulation of motorsports:
http://www.asphaltandrubber.com/news/epa-production-production-racing/
https://petitions.whitehouse.gov/pe...posal-prohibit-conversion-vehicles-racecars-0
http://www.asphaltandrubber.com/news/epa-production-production-racing/
https://petitions.whitehouse.gov/pe...posal-prohibit-conversion-vehicles-racecars-0