A sleek new 3 Series convertible with BMW's first retractable hardtop made its worldwide debut Sunday at the 2007 North American International Auto Show (NAIAS).

The car will be available in the U.S. showrooms starting at the end of March.

"BMW has over 70 years experience in producing dynamic convertibles, and all this experience and our innovative spirit are reflected in this convertible," said Klaus Draeger, member of the BMW Board of Management for purchasing.

The 3 Series convertible features a lightweight steel retractable hardtop, a new series of 6-cylinder gasoline engines with High Precision Injection, and a new interior with more luxury and new detail solutions to increase convenience.

BMW also showed the Hydrogen 7, a flex-fuel vehicle that runs on gasoline and hydrogen fuel, and the new BMW X5, which began arriving in U.S. showrooms at the end of November 2006.