The third-generation Lexus GS sedan (chassis code S190) debuted at the North American International Auto Show in January 2005. It was the first production model to fully incorporate Lexus's L-finesse design ideology, featuring a fastback-like rear roofline, long hood, and short overhangs. Cabin innovations included SmartAccess push-button start, touch-screen navigation, Pre-Collision System (PCS), and dynamic radar cruise control.
Engine offerings included a 3.0-liter V6 on GS 300, a 3.5-liter V6 with available all-wheel drive on GS 350, and a 4.3-liter V8 on GS 430. In 2006, Lexus introduced the revolutionary GS 450h performance hybrid, which combined a 3.5-liter V6 engine with a high-output electric motor for 339 total system horsepower. A 2007 update replaced the GS 430 with the GS 460, featuring a 4.6-liter 1UR-FSE V8 rated at 342 hp paired with an 8-speed automatic transmission.