There is no "silver bullet" to addressing these concerns, said Jeremy Close, cybersecurity and privacy counsel at Kia America.
"We have big targets on our backs," he said. "We operate in a very litigious environment. Everything you say outside of your company can and will be used against you."
Companies need to find the balance between being transparent and protecting secrets.
As over-the-air updates to vehicle software proliferate, they open up new revenue sources for automakers. Upstream Security CEO Yoav Levy said this creates more potential exposure points. "This needs to be more of a continuous effort and a continuous process," he said.
Upstream plans to open its first U.S. security operations center in Ann Arbor, Mich., west of Detroit, as it gears up for an expected rise in threats.
Companies should educate their employees from "the shop floor to the C-suite," said Rebecca Faerber, manufacturing cybersecurity services manager at Ford Motor Co.
"I don't pretend any of us are the same as the national electric grid, but we are critical infrastructure," she said. "And I'm concerned we would make a great test bed for a smart and well-motivated group."
National cybersecurity risks are also on the rise. As vehicles become more connected to smartphones and infrastructure, they become more attractive targets for U.S. adversaries such as China, Russia and North Korea, D'Antuono said.
"Malicious actors" in China have stolen more U.S. personal and corporate data than all other nations combined, including proprietary secrets from businesses that allow the country's state-owned companies to compete "unfairly on the global stage," said D'Antuono.
He urged cooperation and transparency between companies and the government to combat that threat.
Davis is optimistic about increasing cooperation in the industry.
"You already see the industry coming together and collaborating," he said. "We're turning that corner together."