Registrations of new convertibles in the United States have increased 63percent over the past six years, The Car Connection (TCC) website said, citing figures from RL Polk & Co. In an article comparing a variety of models, TCC said that convertible sales reached 310,595 in 2001, up more than 10 percent over 2000. Forty percent of convertibles are bought from June to the end of September, TCC said, adding that the top 10 cities for convertible sales are Los Angeles, New York, Miami, San Francisco, Orlando, Chicago, Philadelphia, Detroit, Washington, DC and Dallas.