The airbag existed on paper decades before most muscle cars ever left the factory floor. German engineer Walter Linderer patented a version in 1951, followed by American John Hetrick in 1953, but neither design worked reliably enough for production. Mercedes-Benz finally cracked it in 1981, pairing airbags with seatbelt tensioners on its S-Class, and dual front airbags didn’t become mandatory in the U.S. until 1998. That timeline means virtually every classic muscle car from the genre’s golden age was built without any form of supplemental restraint at all.