U.S. sales of Ferraris and Maseratis have jumped by 46 percent in the last five years, to 1,200 in 2002. Ferrari isn't alone. Lamborghini, Porsche,Jaguar and other makers of exotic, high-priced vehicles also saw U.S. sales increase throughout the latest recession, according to an Associated Press (AP) report."We've been a little bit surprised by it," said Cristina Bruzzi of Aston Martin, whose NorthAmerican sales rose by 50 percent between 2001 and 2002 despite price tags of $170,000 or higher. "We just haven't seen our customers affected by what's been going on the last few years."Market researchers say there are many reasons for the trend, from an aging population with a growing income to vehicle incentives to the introduction of more luxury vehicles with varying prices, according to AP. High-end luxury car buyers tend to own their own businesses, so they're less susceptible to layoffs. And there's the timeless love affair with luxury cars.As the nation's 65 million Baby Boomers reach their peak earning years and watch their children leave home, more and more are buying high-end vehicles, said George Pipas, sales analysis manager for Ford Motor Co. Before 1997, sales of premium brand vehicles -- including Lexus, BMW andMercedes-Benz -- made up 4 to 6 percent of the total U.S. market, Pipas said. In 2003, premium brands represented 10.3 percent of sales, or 1.75million vehicles.Pipas told AP that automakers have seen the trend coming and expect it to continue for a while, since the youngest Baby Boomers are still in their 40s. Low financing rates, discounts, favorable leasing terms and other incentives also have increased sales of luxury vehicles, as buyers make decisions they might not have before those options were available, according to AP.