During the presidential campaign, Ford Motor became Donald Trump’s favorite example of what’s wrong with U.S. trade agreements and industrial policy.

Indeed, Trump attacked Ford repeatedly for shipping jobs to Mexico, most recently highlighting Ford’s decision to shift all small-car production to lower-cost Mexico.

Trump called Ford’s decision “horrible,” telling crowds in Michigan, “We shouldn’t allow it to happen.” For Trump, hammering Ford for investing $1.6 billion in Mexico was a winning tactic in a broader strategy aimed at convincing voters that he could and would end trade agreements that cost American jobs and restore property to a U.S. Rust Belt hurt by jobs lost to overseas outsourcing and automation.

But Ford is only doing what all car companies do in this global industry – moving production around to where the economics make sense.

Trump also failed to talk about the success of Ford’s joint ventures in China. Year-to-date sales for Ford, Changan Ford and Jiangling Motor Corporation total 966,000 vehicles (up 10 per cent). That growth offsets Ford’s stalled North American business, keeping the company profitable and growing and making it possible for Ford overall to employ hundreds of thousands worldwide.

General Motors is also heavily dependent on its China business, and its divisions elsewhere around the world, as is Fiat Chrysler (FCA). In the car business, it’s go global or go away entirely.

And that’s one reason why the Detroit 3 automakers must surely be nervous about President-elect Trump. They compete in an industry that bets billions on global product plans, investing billions in technologies to mitigate the effects of the auto industry on climate change.

The incoming President Trump, however, has said global warming is a Chinese hoax: “The concept of global warming was created by and for the Chinese in order to make U.S. manufacturing non-competitive,” he famously said in a 2012 Tweet.

Now it’s possible that Trump is just making this up. After all, Politifact found that 70 per cent of what he says is “mostly false,” “false” or “pants-on-fire” false. So during the heat of the campaign he might have taken lying to new heights on only a temporary basis – just to get elected.

The thing is, the auto industry operates on five- to seven-year product cycles that require massive investments and long-range planning. Car companies need to know that they are making the right product and technology bets so that what comes to market years later will be acceptable to regulators and politicians, as well as popular with consumers.

So when a Donald Trump says the North American Free Trade Agreement (NAFTA) should be shredded or renegotiated, car companies cringe. Will Trump really carry through on his NAFTA threats – his pledge to renegotiate NAFTA or terminate it, or impose a 35 per cent tax on products made in Mexico?

And China? Detroit automakers have made big bets on China. Trump says China is a currency manipulator, pushing down the value of its currency to make exports to the U.S. more competitive. Trump’s threats to unilaterally apply new tariffs on Chinese and Mexican imports could result in a trade war that would hurt the Detroit 3.

Energy policy? Trump is a global warming denier. He has said he would neuter rules designed to lower CO2 levels and relax fuel economy and emissions rules put in place by President Obama – rules the auto industry has been working successfully to conform to with new technologies and designs. Without Obama, there would be no Tesla and the incipient electric vehicle boom would not exist at all.

The challenge for the Detroit 3 and all the rest is that Trump is as an unknown with a confusing and contradictory track record. This is in sharp contrast to President Obama.

Early in his first term, Obama laid out strict new fuel economy rules for the auto industry, but set them out over a reasonable time line with goalposts stretching to 2015. The idea, said Obama was not to “further burden an already struggling industry” but instead “help America’s automakers prepare for the future.”

The industry was not thrilled, but as Automotive News reports, then-GM CEO Fritz Henderson conceded that “”GM and the auto industry benefit by having more consistency and certainty to guide our product plans.”

And, indeed, since then, the car business has responded. Automotive News points out that nearly half of the 2015 model year fleet used direct-injection engines, compared with two per cent in 2008, according to the EPA.

“Six-speed transmissions jumped to 57 per cent of the fleet from 19 percent, while gearboxes with seven or more speeds grew to 17 per cent from 2 per cent. In addition, automakers now offer 12 battery-electric vehicles and 13 plug-in hybrids, according to the EPA.”

For the past eight years, the auto industry has had a tough but predictable and even sympathetic Obama to deal with. Trump, often criticized for being erratic, inconsistent, uninformed, incurious and vengeful, promises to be the antithesis of Obama.

No car company executive will say it, but rest assured the prospect of a President Trump terrifies every single one of them.