About this time last year Forbes reported that CEOs at our nation's 500 biggest companies got pay raises of about 16%, or an average of $10.5 million. That's a huge increase and makes the standard 3% for the rest of Americans seem like a drop in the bucket. With shareholder uprisings few and far between, some of these CEO's are given outlandish pay for relatively poor performance, but some have their hands full trying to earn their lofty pay.

When glancing at the automotive industry, it's quickly apparent that Alan Mulally has made a record comeback at the helm of Ford. CEOs at General Motors (NYSE:GM) and Chrysler haven't been as quick to bring their companies back from the dead, but here's a look at how they're earning their lofty salaries.

General Motors
There aren't many companies that soak up as much hatred from the public as General Motors does. After a significant bailout by the U.S. Treasury with taxpayer dollars, it's led to an uphill battle for the company to repair its damaged brand image.

CEO Dan Akerson came over from the telecom industry and immediately had his hands full in the battle to return GM to profitability. Slowly but surely GM is checking things off its list of "to-dos", including completing its IPO in 2010 and recently being reintroduced into the S&P 500.

There's still a lot of work to do at GM. Regarding the task ahead of GM, respected Morgan Stanley analyst Adam Jonas told his clients in a note: "The next 18 months will set the tone for the rest of the decade."

He's exactly right because GM owns the industry's oldest portfolio and has many vehicles that are years overdue for a redesign. Its old portfolio has been a large factor for why GM has lost market share over the last few years. Akerson and his team will be refreshing, redesigning, or replacing 90% of its vehicle portfolio by 2016 – GM's biggest portfolio refresh in history.

In addition to multiple launches of important vehicles, Akerson also has a goal to bump GM's North American operating margins to 10% over the next few years. Last quarter, GM reported a margin of 6.2%, but hopes that the launch of the 2014 Silverado will help boost that number, along with making operations more efficient.

GM's luxury brand, Cadillac, is having a great year in part because consumers are buying up the new ATS model in droves. According to AutoNews, it's been Caddy's biggest surge since 1976 – pretty impressive.

Between Akerson's goal of improving margins, completely refreshing GM's vehicle portfolio, and trying to break even amid the chaos in Europe – he'll have his hands full earning his lofty paycheck.

(NASDAQOTH:FIATY) CEO Sergio Marchionne also has his hands full, finding himself in a unique situation of owning 58.5% of Chrysler after a 2009 agreement. Marchionne is hearing out IPO pitches; it's possible that Fiat could buy out the rest of Chrysler that's held by the United Auto Workers' retiree health care trust.

It's up in the air how exactly it would be handled or when an IPO could take place, but the merger would come at a good time because Fiat has cheap financing available to make the purchase. The move would solidify Marchionne's goal to create a global automaker to compete with General Motors, Toyota, and Volkswagen.

All IPO questions aside, Marchionne still has his hands full coordinating multiple brands around the mess in Europe and with plans to expand Jeep into China. According to AutoNews Europe, Marchionne hopes a Chinese joint venture with Chrysler can produce 100,000 new Jeep models in China. That move would be essential to meeting Fiat's goal of selling 300,000 in the region next year.

Bottom line
Both of these CEO's clearly have many huge projects to execute over the next 18 months. Hopefully both were taking notes as Alan Mulally and Ford made a blueprint for turnaround success without taking a government bailout.

For GM and Chrysler to return from the depths of the recession as valuable investments these CEO's need to make the right decisions – which, historically speaking, is a large risk for investors. But with significant risk comes the potential for greater gains in your portfolio. These two companies offer unique opportunities for investors but require much additional homework and research before buying.

Fool contributor Daniel Miller owns shares of Ford and General Motors. The Motley Fool recommends Ford and General Motors. The Motley Fool owns shares of Ford. 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.