Recently proposed EPA automobile emissions rules could put the brakes on the popular pursuit of converting road cars into race cars for professional and amateur use, says a major automotive trade organization.

The Specialty Equipment Market Association, more commonly known as SEMA, raised the alarm after coming across a passage in the federal agency’s Greenhouse Gas Emissions and Fuel Efficiency Standards for Medium- and Heavy-Duty Engines and Vehicles - Phase 2 proposal that reads:

“Certified motor vehicles and motor vehicle engines and their emission control devices must remain in their certified configuration even if they are used solely for competition or if they become non-road vehicles or engines.”

According to SEMA, which represents the aftermarket parts and custom car industry, this passage means just what it says: Cars and trucks originally built and sold for street use would not be exempt from emissions rules if they are converted into competition vehicles.

And the EPA agrees.

An agency spokeswoman told Fox News that the proposal essentially restates what the EPA already considers to be the law.

“People may use EPA-certified motor vehicles for competition, but to protect public 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,” she said.

She added that the updated rule “clarifies the distinction between motor vehicles and nonroad vehicles such as dirt bikes and snowmobiles. Unlike motor vehicles – which include cars, light trucks, and highway motorcycles – nonroad vehicles may, under certain circumstances, be modified for use in competitive events in ways that would otherwise be prohibited by the Clean Air Act.”

However, in a statement released to the media, SEMA CEO Chris Kersting argued that “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. 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.”

The EPA has not yet discussed how or if it plans to actively police the updated rules.

Race car builders often modify or remove the emissions systems from street legal vehicles to improve their performance. Many purpose-built race cars, including NASCAR Sprint Cup cars and factory drag racers like the Ford Mustang Cobra Jet, are not required to have certified emissions control systems, and the proposed rules do not appear to affect their status.

SEMA Vice President of Governmental Affairs Steve McDonald says the organization wasn’t properly notified of the proposal and originally missed it due to its inclusion in what it considers to be an unrelated rules package, but that it plans to oppose any changes to the status quo through all legal means.

The public comment period on the proposal, which is primarily concerned with the fuel efficiency and carbon dioxide emissions of large commercial vehicles, has ended. The EPA is currently reviewing submissions and expects to publish a final rule in July.

You no longer need to go to a gas station for that biennial emissions test.

On-road vehicle emissions inspection sites have been deployed across Northern Virginia as part of a new program authorized by the Virginia Department of Environmental Quality.

The program, called RAPIDPASS Virginia, lets drivers meet their emissions inspection requirement during daily driving routines.

“Motorists simply drive through conveniently located on-road testing equipment positioned throughout Northern Virginia to have their vehicle emissions measured,” according to a news release from ETEST Corp., which manages the testing centers.

“Owners of well-maintained, clean-running vehicles will receive notification of a passing emissions inspection via mail, or motorists can go online to www.rapidpass.org and enter their license plate number to check if their vehicle has been processed as clean,” the release said.

Inspection fees can be paid online or through the mail.