According to the automotive Website Just-Auto.com, sales of new convertibles in the United States have risen 63 percent since 1996.In 1996, convertibles accounted for only 1.3 percent of all registered vehicles, according to RL Polk & Co. The market share is now 1.9 percent, which is a difference of more than 103,000 registrations a year.Polk's national vehicle registration database says the Ford Mustang is the most popular convertible, with 14 percent of registrations, followed by the Chrysler Sebring with 12 percent. Conversely, in 1997 the Sebring led the pack with 21 percent of all registrations and the Mustang came in second with 11 percent."American consumers' interest in convertibles is back," said Polk analyst Eric Papacek. "Automakers have responded with a greater variety of convertible models than we've seen in the last 30 years. Manufacturers are always looking for ways to inject passion and sophistication into vehicle design. Convertibles, by their very nature, incorporate these elements to enhance the driving experience."