Aston Martin dealerships in the U.S. are in danger of closing due to federal regulations that make two of their models illegal to sell.

DB9 and Vantage models produced after Aug. 31 can't be sold in U.S. showrooms because they don't meet side air bag standards from the National Highway Traffic Safety Administration, Reuters reported.

Citing potential "substantial economic hardship," Aston Martin has requested exemptions for the exemptions for the DB9 model until September 2016 and for the Vantage until September 2017.

The new side air bag standards, which the NHTSA has been phasing in since 2010, are intended to protect occupants from side crashes into fixed objects such as telephone poles and trees.

The NHTSA is able to provide exemptions for select manufacturers that sell fewer than 5,000 vehicles each year; according to Aston Martin, the carmaker sold 4,200 vehicles worldwide in 2013.

The DB9 and Vantage titles are top sellers for the British automaker and essential for company growth as it continues to recover from the recession, Jalopnik reported via Bloomberg.

"The financial viability of Aston Martin dealers is very much in question," James Walker, chairman of Aston Martin's U.S. dealer advisory panel, wrote in a petition to the NHTSA. "If dealers make the decision to shutter the franchise, a very likely outcome, the impact on employment is significant."

Headquartered in Gaydon, England, Aston Martin has stayed independent for its 101 years of being a company, standing as one of the few luxury automakers not operating under a larger umbrella.

The DB9 model starts at $186,525, while the Vantage is priced at $119,525.

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