* The manufacturers themselves: Pontiac (with the GTO), Ford (with the Mustang), Plymouth (with the Road Runner), Chevrolet (with the Camaro and Chevelle SS), and others all played significant roles in popularizing the muscle car concept. Each company contributed its own designs and marketing strategies.
* Technological advancements: Advances in engine technology, particularly high-performance V8 engines, were crucial.
* Marketing strategies: The focus on affordability and high performance combined with effective marketing campaigns helped solidify the muscle car's position in the market.
Therefore, attributing the invention to a single person is inaccurate. It was a collective effort driven by several factors.