The Lexus IS sedans show a strong family resemblance to the Lexus GS models while establishing their own distinctively sporty identity. A notably wide stance and long wheelbase, coupled with tightly drawn bodywork, give the IS an athletic, road-hungry yet sophisticated style. Carefully shaped body contours, a subtle ducktail-curved trunk lid and "air kick" tail lamps contribute to a low 0.28 coefficient of drag (Cd).

A highly rigid body structure is the starting point for controlling noise intrusion. Strategically placed noise-suppression materials, including special window and door seals, acoustic windshield glass and asphalt sheeting, take over from there.