They're baaaaaaaack.

U.S. consumers, buoyed by a surging stock market, steady, if not gangbusters, job growth and a flock of new affordable cars, are back at dealerships plunking down their cash or credit to drive off in a new set of wheels.

Kia Motors America set an all-time sales record in March, passing the 50,000 mark for the first time. Kia's performance was driven by strong demand for the brand's two U.S.-built products, the Optima midsize sedan and Sorento CUV built at Kia Motors Manufacturing Georgia, as well as the ongoing popularity of the Soul urban passenger vehicle. Kia's U.S. sales are up 31.8 percent year-to-date.

"Kia is on a tear, and has had a tremendous surge in consideration on our website," said AOL Autos Editor-in-Chief David Kiley. "They have done everything right for a while--good provocative design like the Kia Soul, value pricing, increasing quality and engaging advertising to get people to notice," said Kiley.

General Motors passed an environmental milestone of sorts in March, when it became the first U.S. automaker to sell, in a single month, more than 100,000 cars that can achieve 30 miles per gallon in highway driving. About 40 percent of GM's March sales were of these fuel-efficient cars, said Mark Reuss, GM president for North America. "This is a whole new General Motors," noted AOL's Kiley. "GM, back to being the sales leader, has also become a bonafide industry leader in technology that has pushed up fuel efficiency across their entire lineup."

Overall, General Motors, the world's biggest automaker by sales, reported March sales of 231,052 vehicles in the United States, up 12 percent from a year ago. Ford Motor Company, the number-two US automaker, posted a 5 percent rise in sales, to 223,418 vehicles, its strongest sales performance since 2007.

Ford said the fuel-efficient Focus was its hottest-selling car, with sales up 78 percent and setting an all-time sales record of 28,562 units. Chrysler Group, controlled by Italy's Fiat said U.S. sales surged 34 percent to 121,730 units, its highest level since March 2008. Toyota Motor Sales U.S.A., Inc., today reported its best March results since 2008 with sales of 203,282 units, an increase of 11.2 percent compared to March 2011.

"Toyota dealers had their best-selling month outside of Cash for Clunkers since the pre-recession days of August 2008. Camry and Prius also continue to shine as both set records, including Camry's best March ever and an all-time high for Prius sales," said Jeff Bracken, vice president of Toyota Division sales.

Sales of luxury vehicles are tracking healthy. The BMW Group reported its best first quarter of all time in the U.S. with 75,729 vehicles sold, up 13% from last year. That includes sales of both BMW and MINI branded vehicles.

"The 1st Quarter record affirmed our increasing sales momentum and shows that customers feel more confident about the future," said Ludwig Willisch, President and CEO, BMW of North America. "The year is still young and BMW alone will introduce in 2012 more new and refreshed models in the U.S. than it ever has before in any one year making us strongly optimistic about the months ahead."