Even before the free-trade agreement took effect 24 years ago, central Mexico was gaining a reputation as an alternative to the established auto clusters near the Mexican capital and along the nation's northern border with the U.S.
Nissan, for instance, opened its first Bajio plant in 1982 in the capital of Aguascalientes.
Shortly after NAFTA took effect, GM moved pickup production from crowded Mexico City to Silao, Guanajuato, in 1995, and Honda set up in El Salto, Jalisco, to make the popular Accord sedan. GM added another assembly plant in San Luis Potosi in 2008.
Guillermo Romero Pacheco, secretary of economic development for Guanajuato, said GM's move was a watershed for the state, which went all-in to draw foreign investment in the wake of NAFTA.
Then-Guanajuato Gov. Vicente Fox, a pro-trade businessman who later became Mexico's president, promoted creation of an automotive cluster to join the shoe industry, mining and agriculture as economic drivers.
In addition to financial incentives to lure foreign manufacturers, Guanajuato and other states offered worker training programs tailored to the needs of individual companies. The Bajio also offered a sizable labor pool relative to northern Mexico, which had already industrialized.
Logistics also favor the region. It lies at the junction of the nation's two major railroads, with access to ports on the Pacific and Gulf coasts.
As Japanese automakers moved more production to North America to be closer to their customers, the Bajio was ready with land, workers, incentives and training.
Romero said about one quarter of the 250,000 jobs created in Guanajuato from 2012 to late 2017 came from the auto sector. Another quarter came from other industries. And those numbers don't include indirect jobs from the auto industry, such as the army of food vendors including Malagon in Apaseo who run mom-and-pop operations.
The result, according to official data, has been a lower rate of extreme poverty, rising family incomes and "many, many jobs," Romero said.
Workers in the area agree, but with a caveat. Automakers, suppliers and related industries such as metalworks are constantly hiring, but it's because of rock-bottom wages and heavy turnover, they say.