The slightly larger cabin of the LS 430 is sandwiched between an extended hood and blunted tail. A sleek, shapely skin makes the big Lexus appear long and low. Chiseled edges define a bold front grille and stepped hood, all of which give the LS 430 a substantial appearance.

A trapezoidal grille is rimmed in bright chrome. Gleaming multi-lens headlamps wrap around each corner, forming exaggerated triangles. They stand above the thick chin-leading bumper. A thin bead of chrome segments the bumper at the top. Smooth creases in the sides of the grille thrust it forward, and the hood bulges in the center, suggesting power.

Like its predecessor, the LS 430 presents a subtle profile, a conservative treatment where shoulders roll fluidly into side panels with only a hint of flare around the wheelwells. The cant of the windshield echoes the slant of the backlight (rear window). Curvaceous rear pillars blend seamlessly into rear flanks. A conventional tail features a horizontal deck leading to a vertical back panel with oversized corner taillamps, camouflaging the mass of the trunk.

Despite these quietly linear lines, the big Lexus is so streamlined that it earns a 0.25 coefficient of drag, one of the best drag coefficients of any vehicle built. Its superb aerodynamic shape enables it to slice through still air so smoothly, it practically negates wind noise. The slick exterior form is further enhanced by the remarkable fit of the body panels. Although Lexus has long been recognized for superior fit and finish, the quality achieved by the LS 430 reaches a new dimension. Engineers used a supercomputer to digitize all body surfaces, then worked out new fit tolerances ten times more precise than on the previous car.