The Mercedes-Benz S-Class remains the ultra-luxury car against which other ultra-luxury aspirants are judged. That's impressive given that it was last redesigned for model-year 2000. The S-Class has been mildly face-lifted for 2003. The Mercedes S-Class is a beautiful line of cars, sleek and aerodynamic. They are smaller yet roomier than the bulky pre-2000 models they replaced. And they are extremely sophisticated. Microprocessors and onboard sensors instantaneously determine forces acting upon the car, filter the data, and adjust the handling. There's much technology here and learning all of the features takes some time. The Mercedes-Benz S430, the most popular model, offers plenty of power for quick passes, merging into fast freeway traffic, and accelerating out of corners. It exudes the tremendous presence of a Mercedes S-Class. The S500 delivers much more responsive performance, with crisp acceleration that should please any closet hot-rodder. The top-level S600 and the high-performance S55 AMG get even more power for 2003. A lot more power. As if they needed it. Fast traffic is a description fits an S600 and an S55 AMG. The S600 represents the ultimate in Mercedes-Benz luxury and power. The S55 AMG is a limited-production high-performance model. For 2003, the S-Class comes with new safety systems that can actually anticipate a collision, and prepare driver and passengers to get through it as safely as they possibly can. Electric seat belt tensioners are activated, and the power seats adjust to a lower and more upright position. Mercedes-Benz calls this system Pre-Safe, and points out that it is the only system in production today that engages before the impact, when milliseconds can minimize the energy spikes that cause serious injuries. Also new for 2003 is the availability of 4Matic all-wheel drive.