The new USMCA trade deal between the U.S., Canada and Mexico goes into effect Wednesday.

For export manufacturers in Sonora, Arizona’s neighbor to the south, there was no shortage of anxiety and uncertainty as the old NAFTA trade deal was being renegotiated. Gerardo Vazquez, head of Index Sonora, which represents such manufacturers, said it’s a relief to have clear trade rules in place.

“As far as the rules of origin are concerned, it’s a big challenge,” he said. “We need to incorporate regional content.”

But those higher requirements for regional sourcing for car manufacturing could also mean substituting Asian manufacturers with suppliers in Arizona or elsewhere among the three signatory countries, according to Vazquez.

Mexico is Arizona’s most important trading partner, with combined exports and imports totaling roughly $17.5 billion in 2019, according to federal data.