Mercedes-Benz's GLS has earned a clear reputation among enthusiasts as the SUV that refuses to compromise, offering genuine full-size capability without asking its occupants to tolerate anything less than a flagship experience. This example is the 400d in AMG Line trim, powered by a 3.0-litre inline-six diesel producing 330 HP and 700 Nm of torque, figures that give the GLS a composed, almost effortless quality at any speed, with drive channelled through a nine-speed automatic and permanent Four-Wheel Drive. Having covered just 15,000 km from new, the condition here reflects exactly the kind of low-use, well-kept example that is genuinely rare in a vehicle of this scale. The AMG Line specification sharpens the exterior presence considerably, and inside the cabin the standard is thoroughly upheld with powered, heated, and ventilated front seats featuring memory function, 64-colour ambient lighting, and the MBUX dual-display setup that remains one of the more intuitive arrangements in the class. Comfort and technology are equally well addressed, with AIRMATIC air suspension and adaptive damping doing the heavy lifting on ride quality, while the Burmester surround sound system, wireless Apple CarPlay and Android Auto, wireless charging pad, and hands-free power tailgate round out a specification that asks very little of a new owner. As a package, this is a coherent and well-considered GLS that is ready to use from day one.