Development on fourth generation LS began in 2001 under program code "250L", with the design process being done under Yo Hiruta from 2002 to late 2003, with the final production design being frozen in 2004. In October 2005, Lexus premiered a gasoline-electric hybrid concept car, the LF-Sh (Lexus Future-Sedan hybrid), at the Tokyo Motor Show, publicly previewing the next Lexus flagship with a concept version for the first time. Introduced at the January 2006 North American International Auto Show for the 2007 model year, the fourth-generation Lexus LS became the first Lexus model to be produced in both standard and long-wheelbase versions. Using an all-new platform, the LS 460 (USF40) uses the standard wheelbase, while the LS 460 L (USF41) features a stretched wheelbase. The fourth-generation models' technical specifications were shown in greater detail at the Geneva Motor Show in February 2006. A hybrid version, LS 600h L (UVF46), was previewed at the New York International Auto Show in April 2006. At its introduction in 2006, it won the Car of the Year Japan award for the second time.