Heading into the planning of the LS 430, division executives concluded that the previous LS redesign had been too restrained in its approach. The LS 430 development team, led by chief engineer Yasushi Tanaka, accordingly opted for a more thorough exterior, interior, and technological redevelopment. The development of the LS 430 took four years. Selected from 16 different concept designs, the resulting vehicle of December 1997—when the final design (by Akihiro Nagaya) was approved—saw the sedan's dimensions increase in terms of wheelbase and height. The exterior featured a larger grille with rounded edges, quarter windows on the rear doors, and rounded trapezoidal headlamps. The body was also more aerodynamic than previous LS sedans ("C""d" 0.26; 0.25 with air suspension), and was the product of wind tunnel testing at facilities used for Shinkansen bullet train development. A wheelbase stretch resulted in more interior volume and allowed the engine to be positioned further aft for better balance. Trunk space was increased by one-third due to repositioning of the fuel tank.