GM's taxpayer-funded bailout earlier this year threw cold water on any hopes of a turnaround. "We were hit with a perfect storm, with the industry's low run rate, with the domino effect of the Wall Street situation," a weary Saturn general manager Jill Lajdziak explained to reporters at the Detroit Auto Show earlier this year. "That doesn't mean Saturn's going anywhere," she insisted. Then, nearly four months ago, an eleventh-hour plan to save Saturn from the consequences of GM's bankruptcy was announced. Penske, an auto distributor, would sell the three best-selling Saturns—the Aura sedan, the Vue, and Outlook crossover SUVs—on behalf of GM for two years. A third-party manufacturer would eventually begin providing new cars badged as Saturns in 2011. No partner came forward, and the deal collapsed.

Even if the Penske scheme had gone through, it may have been too late to save Saturn. In its best year, 2007, the brand sold 240,000 cars. So far this year, Saturn has sold just 57,223 vehicles. And according to analysts at Grand Rapids, Michigan-based forecasting firm IRN Inc., about 10 percent of those sales were a result of the government's generous Cash for Clunkers program this summer. Edmunds.com's Krebs says that as of last month barely 1 percent of prospective car buyers were researching Saturn, as the bad news took a toll on the consumer perception of the brand. A year before, the number had been between 10 percent and 13 percent.

Ultimately, Saturn's demise comes as the American auto market is beginning to sharply recalibrate. According to financial analyst firm HS Global Insight, by 2015, Detroit automakers will sell around 6.5 million vehicles, just over half what they sold in 2000. No top auto manufacturer will command more than about 20 percent of the American market, whereas GM vehicles once accounted for over 50 percent of U.S. sales. In other words, Saturn will likely be remembered as the last full-bore attempt by an American manufacturer to stem these perhaps inevitable market-share losses.

Saturn is survived by a struggling, restructured GM made up of four brands: Chevrolet, Cadillac, Buick, and GMC.