The automotive industry is one of the biggest sectors of the American economy, and one of the largest sources of jobs among all U.S. manufacturers. As such, it has remained high on the agenda for President Donald Trump — who has now met twice with automotive leaders and alternately scolded and praised the industry in his tweets and at news events.

“We’re entering the most turbulent era since I started watching the auto industry — and the president could dramatically change the game,” David Cole, director-emeritus of the Center for Automotive Research, told NBC News.

Trump has dangled carrots — like the proposed corporate tax cut announced this week, and a possible rollback of strict new mileage standards. He’s also wielded a big stick, notably the threat of hefty import taxes and the elimination of the North American Free Trade Agreement. But as the new president approaches his first 100 days in office, there’s general consensus among a wide range of industry insiders and analysts that Trump has yet to make any real impact.

Though the president’s push to roll back regulations and to boost spending on roads and other infrastructure projects appeals to even the more liberal among a traditionally conservative automotive elite, “Everyone is aching for substantive results,” stressed Mike Jackson, the outspoken CEO of America’s largest automotive retail chain, Ft. Lauderdale-based AutoNation. “On the legislative side, other than (the confirmation of Supreme Court Justice Neil) Gorsuch, it simply hasn’t happened yet.”

Here’s a look at specific areas of interest to the auto industry and what the president has so far said, if not done:

Jobs

As a candidate, Donald Trump staked out manufacturing jobs as a centerpiece of his campaign. He quickly took on Ford for planning to ship operations to Mexico, later adding General Motors, Toyota and other carmakers to the list of those who could be hit with as much as a 35 percent tariff on imported vehicles and parts.

Even before the January inauguration, as president-elect, Trump began taking credit for a slew of industry announcements, such as Ford’s decision to cancel the Mexican plant and GM’s $1 billion investment in several Midwest plants.

"When the U.S. auto economy catches cold, the auto industry comes down with pneumonia."

In fact, Ford’s move was “already in the pipeline” well before the election, said Joe Hinrichs, Ford’s President of the Americas. And other makers echoed that, noting that with rare exception, investment and job plans announced in recent months were generally in the works for as much as three years.

That said, most auto assemblers and parts makers said they would be happy to bring more production back to the U.S. But, for the most part, “anything we bring back will be super-automated,” said Marina Whitman, a one-time GM executive vice president who now serves as a professor of Business Administration and Public Policy at the University of Michigan.

Parts plants that once might have employed hundreds, even thousands, of workers, she said, might only needs dozens going forward, high levels of automation to offset lower overseas wages.

Trade

Mexico took a drubbing during the campaign, with candidate Trump declaring his intention to eliminate or completely renegotiate the North American Free Trade Agreement. As president, he immediately scuttled a trans-Pacific deal, but so far, there’s been no clear move on NAFTA other than lobbing threats at Mexico and, this week, initiating new tariffs on Canadian softwood imports.

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Related: Trump Now Threatening Automakers in Canada and Germany

And that’s good news for the auto industry, which would like to see a North American trade deal stand just as it is. In fact, some of the most vociferous lobbying in favor of NAFTA has been led by auto dealers, AutoNation’s Jackson calling threats of an import tax “a cockamamie science experiment gone wrong.”

“I don’t think (Trump) understands the incredible spider web of the intricate auto industry supply chain,” added Joe Phillippi, head of AutoTrends Consulting, noting that it’s not unusual for automotive parts and components to repeatedly cross the border before a finished car rolls off the line. That would translate into a significant challenge for automakers — and significantly higher new vehicle prices for consumers — which is why many industry observers expect the subject of NAFTA might drop low on the president’s priority list and see, at most, only modest revisions.

Auto Sales and the Economy

Anything that might impact new car sales worries the auto industry, especially at a time when demand is slipping after three years of record growth. Preliminary estimates anticipate April will have seen another 2-3 percent dip.

A modest decline will have little impact on the industry, as most manufacturers have been building that into their planning. But a sharper slump would be risky, especially when it comes to new investments and the jobs the president keeps promising.

As a result, industry leaders are watching to see if Trump delivers on two key promises: infrastructure spending and tax cuts. The former would punch case into the economy and boost demand, in particular, for high-profit trucks. A 15 percent top corporate tax rate, meanwhile, could mean billions in additional earnings.

Related: Here's What We Know About Those Tax Cuts

Some doubt Trump can deliver on both, especially without solving another issue that has so far proved insurmountable: the replacement for Obamacare. The worst scenario would see all those efforts fail, leading to growing consumer caution and a chilling of the economy. As the old Detroit adage goes, when the U.S. auto economy catches cold, the auto industry comes down with pneumonia.

Fuel Economy and Other Regulations

Cutting government rules and red tape has been another Trump rallying that has resonated with the auto industry, something “connecting him with industry leaders,” said CAR director-emeritus Cole.

During a meeting at the White House just days after the inauguration, Ford CEO Mark Fields took aim at one particular set of rules, warning the new president that as many as 1 million jobs were at risk if the administration didn’t roll back the Corporate Average Fuel Economy, or CAFE, standard the Obama Administration wanted to raise to 54.5 mpg by 2025.

The White House has ordered the EPA to reopen a so-called mid-term review that could eventually lead to a reduction in the numbers, or a delay in implementation. Ironically, Ford CEO Fields’ lieutenant, President of the Americas Hinrichs, told NBCNews that the impact of any change is likely to be minimal.

"Trump seems to be getting a huge dose of reality: Administration 101.”

“With the typical industry product cycle, which is five to six years, what we’re going to launch (in 2024 to 2025) is already in the pipeline,” Hinrichs said, adding that the most a rollback likely would now do is let automakers shift their model mix. In other words, if consumers are still demanding big trucks mid-decade, automakers would sell more of them and fewer hybrids and EVs.

Consumer groups, such as the Sierra Club are up in arms about the CAFE review, but Nissan CEO Carlos Ghosn said they shouldn’t be worried. “No matter what happens in the U.S., we will not change any of our plans for electrified vehicles and more efficient vehicles.” That’s because automakers rarely develop products for just one market anymore. If China and Europe still want EVs, the U.S. will get battery cars, too.

More to Come?

The Trump administration has yet to weigh in on broader auto emissions and safety regulations, issues that Obama’s Secretary of Transportation, Anthony Foxx, fears could see a “setback” for the country on a variety of fronts. Safety and environmental advocates, in particular, fear what could happen in light of what has happened in recent years, with issues such as the Volkswagen diesel scandal, the Takata airbag scandal, and the GM ignition switch scandal.

Related: NAFTA Whiplash Could Hurt American Economic Interests

Many within the industry would counter that the government needs to step back from its aggressive oversight role, something the new president has suggested he supports.

But observers on both sides suggest that change has and will remain difficult. Trump “seemed to have had the notion that if the president waved a magic wand it would happen immediately,” said Professor Whitman. “He seems to be getting a huge dose of reality, Administration 101.”

On the whole, those who would offer up a grade for those first 100 days said Trump’s handling of the auto industry rated a “C,” at best, with many calling for an “Incomplete.” More than a few said the Commander-in-Chief still needs to learn how to be “more presidential,” with a broad consensus that Trump needs to stop tweeting and focus on leading.