There's plenty of pessimism among Wall Street and Main Street investors about the state of the U.S. auto industry. While sales are currently near all-time highs annually, we're almost certainly at the peak of the cycle, and that means a slowdown ripple effect for companies such as American Axle Manufacturing (NYSE:AXL) is coming. Such is life in a cyclical industry.

But that doesn't mean all hope is lost for long-term investors. Does American Axle's incredible third quarter prove the point? Let's dig in.

By the numbers

Starting from the top, American Axle (AAM) posted revenue of $1.72 billion during the third quarter, which beat analysts' estimates calling for $1.62 billion. American Axle also beat on the bottom line with adjusted earnings per share checking in at $0.86, well above analysts' estimates of $0.64 per share. Comparing those results to the prior-year quarter reveals some explosive growth: Revenue, net income, and free cash flow jumped 70%, 40%, and 61%, respectively, over the prior year.

The strong performance was enough for management to boost its full-year guidance. American Axle now expects full-year revenue to check in between $6.2 billion and $6.25 billion, compared with prior guidance of about $6.1 billion. Management also said adjusted EBITDA is expected to check in at the high end of guidance, about $1.1 billion.

A Parked Ford Mustang with American Axle products and brand images

Image source: American Axle.

"AAM's third-quarter performance was highlighted by continued sales growth, business diversification, and cash flow generation as a result of our recent strategic actions and the realization of our new and incremental business backlog," said Chairman and Chief Executive Officer David C. Dauch in a press release.

While the third quarter trounced prior-year results, investors have to remember that much of the performance was fueled by the acquisition of Metaldyne Performance Group (MPG). Nothing wrong with that, as acquisitions can be a great way to expand if done right, and for American Axle, it helps lessen its dependence on General Motors' (NYSE:GM) business. Remember that American Axle remained under General Motors' umbrella until the early 1990s, and the business connection remains a huge part of the company. Not only did the MPG acquisition drive American Axle's total results higher, but the company also did more than $1 billion of non-GM sales, or 59% of total sales -- both quarterly records.

The question remains

Does this strong third quarter, and an acquisition on track to generate $100 million to $120 million of synergies by the first quarter of 2019, make American Axle a buy right now? The market sure isn't convinced, as American Axle trades at a paltry trailing-12-month price-to-earnings ratio of 6.32, a discount to many of its competitors. There's nothing wrong with American Axle's business as it stands, but if the company is going to convince investors it has a growth story, it might need to make a splash in the driverless-vehicle technology pool.

One great example of an automotive-parts supplier that's doing just that is Delphi Automotive (NYSE:DLPH), which has recently announced a spin-off of its powertrain division and has intensified its focus on developing driverless-vehicle technology and electronics systems. Further, Delphi recently announced an acquisition of nuTonomy, a leading start-up in driverless technology that will bring in 100 talent-rich employees, including 70 engineers and scientists, to roughly double Delphi's current 100-member autonomous-driving team.

Currently, business is good for American Axle, and it shows in the company's third quarter. But it could continue trading at paltry P/E ratios until it convinces investors it has a vision for the rapidly changing automotive industry -- and so far that remains elusive.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.