HAMBURG, Germany — Hangar doors slid open to reveal a fleet of white Mercedes-Benz vehicles arrayed on a rain-slicked runway.

As fireworks shot skyward, an imposing gray sedan zoomed forward onto a temporary stage, delivering Alicia Keys, in a dark floor-length evening gown, to the piano where she performed with a local backup band, the Hamburg Symphony.

Befitting the flagship of the Mercedes line, the premiere of the new S-Class at a vast Airbus jetliner factory here on Wednesday night was a grandiose event. Always a showcase for luxury appointments, this latest incarnation of the S-Class is notable for much more than features like the so-called hot-stone massages offered by its reclining rear seats. Or the Wi-Fi. Or the cup holders that keep drinks warm or cold.

The 2014 S-Class, which goes on sale in September at an estimated starting price of $100,000, is a significant advance in the development of autonomous autos. That is, while it still requires a human behind the steering wheel, in the right conditions the car can steer itself through city traffic or drive on the highway at speeds upward of 120 miles an hour using an array of radar, infrared and optical sensors to track lane markings or the car ahead — even around curves.