Weekend racers and their $79,000 Mustang Boss 302R were almost sidelined by new rules from the EPA.

The roar coming from weekend racers today isn’t them readying their cars for the track, but from the drivers as the Environmental Protection Agency abandoned plans to prohibit the modification of street-legal car for racing competitions.

After months of denials about its intentions to regulate auto racing, the EPA decided it was necessary to stick its nose into the world of the part-time racing circuits and events around the country, but what kind of changes were coming were unclear.

The lack of clarity caused House Energy and Commerce Committee Chairman and Michigan Rep. Fred Upton (R-St. Joseph) to send a letter to EPA Administrator Gina McCarty asking for clarification on the agency’s plans.

Upton’s letter wasn’t the only feedback the agency received: weekend racers, state attorneys general, the Global Automakers Alliance and former presidential candidate Marco Rubio joined in to express their concerns about the pending, but still unknown changes being considered.

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However, the indications were that the changes would have been so significant they would have nearly wiped grassroots racing and threatened a $30 billion parts industry.

The problem stemmed from language the EPA put into the Clean Air Act’s Heavy-Duty Greenhouse Gas rules, which stated “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.”

EPA claimed the new language was necessary to clarify the act’s regulation of vehicle greenhouse gas emissions. Opponents of the move claimed the agency was rewriting 46 years of law that had exempted race cars. The move mobilized folks to start a national petition to rescind the EPA’s rules, which garnered more than 168,000 signatures. Congressional hearings and grassroots protest ensued.

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The move rescind the plan isn’t enough for those threatened by it: they want permanent change.

“We want to thank Congress for pushing EPA to withdraw an ill-conceived proposal,” said Chris Kersting, head of the Specialty Equipment Manufacturer’s Association (SEMA), according to the Detroit News. “However, confusion reigns. Only clarifying legislation … will confirm that such activity is legal and beyond the reach of future EPA regulations.”

They may get their wish, as a bipartisan effort is underway in the form of the RPM Act – Recognizing the Protection of Motorsports – that was introduced last month. However, with the EPA almost apologizing for the effort that it described as an attempt to clarify its position only lead to more confusion.

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The agency said it will refocus its energy on “reducing pollution from the cars and trucks that travel along America’s roadways and through our neighborhoods.”