Buick

Strong sales of new SUVs, like the Buick Envision, have so far helped offset an overall sales slump in China. But GM's exposure to the slowing Chinese market was one of several concerns we raised about the General in 2015. Image source: General Motors.

General Motors (NYSE:GM) had a good year in 2015, all things considered. While the stock didn't take off, GM reported solid earnings and strong sales of its most-profitable products in both the U.S. and China. Even better for investors with a longer-term perspective, CEO Mary Barra and her team continued to make good progress on their plan to significantly boost GM's earning power by early next decade.

But that doesn't mean everything went right for the General in 2015. Here's a look at some of the not-so-good stories we tracked here at The Motley Fool this past year.

Some tough questions for GM in 2015
Strong truck sales led analysts to believe that GM would report a nice result in the first quarter. But the General's $945 million net profit came in well below estimates, and the stock quickly dropped 3% on the news. 

What happened? Some unfavorable (and unanticipated) exchange-rate moves hurt, as did a sharp drop in South American auto sales, as Brazil fell into a deep recession. 

A Tough Earnings Miss for General Motors Company

We revisited those results a few weeks later when GM arch-rival Toyota (NYSE:TM) reported blowout first-quarter earnings, thanks, in part, to being on the other side of some of those big exchange-rate moves. 

Why Can't General Motors Earn Profits Like Toyota's?

GM's massive presence in China has been a bright light for the General for several years. It's a great success story. But with China's new-car market clearly slowing down earlier this year, we spent some time worrying about just how badly that would affect GM's bottom line. 

Is General Motors Headed for a Crash in China?

How Badly Will the China Slowdown Hurt General Motors?

As it turned out, good sales of some new higher-profit-margin SUVs helped offset the overall slowdown in sales, and keep GM's China profits strong. But China continues to be a worry for GM investors as we head into 2016.

Another concern is looming: As good as U.S. auto sales have been in recent months, there are some reasons to think that the market is at, or near, its cyclical peak. Sales may stay strong for another year or more, but some automakers may find the temptation to discount their way to sales gains irresistible.

To its credit, GM has been very disciplined with incentives this year. Its profit margins in North America have been outstanding, in part because of its newfound conservative approach to discounts. But if GM needs to boost discounts to stay competitive with aggressive rivals, that could cut into margins. 

That's one of the concerns we looked at way back in February. Expect it to be revisited during the next year or two.

3 Reasons General Motors Company's Stock Could Fall

GM's rush to embrace advanced technology has been a good thing, for the most part. GM is set to introduce a new electric car, the Chevrolet Bolt, that is expected to have 200 miles of range at a price of around $30,000. That will be a big step forward for affordable electric cars.

But it comes at a price: GM partner LG Chem (NASDAQOTH:LGEAF) is essentially the co-developer of the Bolt. LG isn't just supplying the batteries; it's also supplying the entire powertrain, the instrument cluster, and other major components.

Chevrolet Bolt Ev Concept

The upcoming new Chevrolet Bolt electric car includes a lot of parts developed and manufactured by GM partner LG Chem. Image source: General Motors.

That raises a question that we raised earlier this year: As GM becomes more dependent on high-tech partners for key systems in its cars, is it at risk of "losing its soul" -- of becoming simply a commodity manufacturer of platforms for the technology of others?

Is General Motors Selling Its Soul to Apple and Google? 

That point hasn't arrived yet. GM's cars still have plenty of GM-ness in them. But expect this topic to be something we discuss more and more during the next few years, and not just with respect to General Motors.

John Rosevear owns shares of General Motors. The Motley Fool recommends General Motors. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.