Mercedes-Benz's S-Class occupies the top of the full-size luxury saloon segment, and the W222 generation in AMG Line trim represents the model at its most complete. Power comes from a turbocharged inline-six producing 340 HP and 700 Nm of torque, sent to the rear wheels through a nine-speed automatic, and the result is effortless, unhurried progress that suits the character of the car entirely. What defines the S-Class above almost everything else is the AIRMATIC air suspension with adaptive damping, which reads and responds to the road continuously and delivers a ride quality that remains genuinely difficult to match at any price. The AMG Line specification adds a more purposeful exterior stance and interior treatment, while inside, the cabin is fitted with Nappa leather, heated and ventilated front seats with a massage function, and a Burmester surround sound system that sets the standard for in-car audio. A panoramic sunroof, heads-up display, and 12.3-inch infotainment touchscreen complete the comfort and technology picture, while Distronic Plus adaptive cruise, blind spot monitoring, lane keep assist, and a 360-degree view camera take care of the safety side of the specification. Sourced from the Japanese domestic market, where these cars are maintained with particular care, this is a thoroughly specified S-Class that makes a composed and convincing case for itself.