The 2005 Cadillac STS is a midsize luxury sedan, part of the first generation that was launched in 2005. This rear-wheel-drive car, with an optional all-wheel drive, is equipped with either a 255-hp V6 or a 320-hp Northstar V8 engine, mated with a five-speed automatic transmission. Two trims were offered, the V6 and V8. While both came with impressive standard features such as leather upholstery and dual-zone automatic climate control, the V8 trim introduced advanced options like adaptive cruise control, a navigation system and a surround-sound audio system. The STS had a well-received debut as it marked Cadillac's return to compete with German luxury brands.