UPDATE: The EPA has responded to SEMA's opposition to a proposal regarding emissions devices in road cars that converted to racecars. The EPA claims it's merely attempting to clarify current language in laws that are already in place.

"People may use EPA-certified motor vehicles for competition, but to protect health from air pollution, the Clean Air Act has -- since its inception -- specifically prohibited tampering with or defeating the emission control systems on those vehicles," said EPA spokeswoman Laura Allen, in a statement.

While it seems unlikely that the EPA will target racecars on the track, the agency appears it will clamp down on vehicles equipped with illegal emissions devices being driven on public roads (again, nothing new).

"In the course of selecting cases for enforcement, the EPA has and will continue to consider whether the tampered vehicle is used exclusively for competition," Allen said. "The EPA remains primarily concerned with cases where the tampered vehicle is used on public roads, and more specifically with aftermarket manufacturers who sell devices that defeat emissions control systems on vehicles used on public roads. "

Even still, SEMA is convinced the proposal would be detrimental to motorsports and the aftermarket industry and will continue to oppose the legislation. The EPA says it will review and consider public comments before releasing a finalized version of the proposal this summer.

The Environmental Protection Agency is attempting to pass regulations that would prohibit the conversion of street cars into race cars. Meant as an attempt to curb greenhouse gases, the proposed regulation will significantly impact racing enthusiasts and the aftermarket industry should it pass.

Cars currently used strictly for racing are exempt from the EPA's emissions standards set for normal street vehicles. That said, the Specialty Equipment Market Association is fighting the proposal and considers it a "threat to modified race cars and parts suppliers."

SEMA reports the proposal was bundled in with an unrelated legislation titled "Greenhouse Gas Emissions and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles--Phase 2." According to SEMA, the proposal would also prohibit the sale of emissions-related parts for use on converted vehicles. The EPA plans to release a finalized version of the proposal this summer, while SEMA states it will continue to fight the proposal's passage.

"This proposed regulation represents overreaching by the agency, runs contrary to the law and defies decades of racing activity where EPA has acknowledged and allowed conversion of vehicles," said SEMA CEO Chris Kersting in a statement. "Congress did not intend the original Clean Air Act to extend to vehicles modified for racing and has re-enforced that intent on more than one occasion."