US$89,500.00 Advertised in period as “The Most Elegant Motorcar in the World”, the W189 Mercedes-Benz 300-series was regarded by many to be the finest engineered and constructed automobile of its time. Early on in production, the 300 earned the nickname “Adenauer”, from the German Chancellor of the same name who had no fewer than six in his fleet. Typically for Mercedes-Benz of the same era, the 300 was substantially strong and overbuilt. Revised and enhanced through several series, the final iteration being the W189, or the 300d, had several distinct features that set it apart from earlier models. For starters, the new, longer hood gave the car a more graceful look, while providing room for an updated version of Mercedes-Benz’s 3-liter SOHC six-cylinder engine now fitted with Bosch fuel injection derived from the 300SL sports car. The wheelbase grew by four inches to align the car with the likes of the Rolls Royce Silver Cloud and afford rear seat occupants plenty of additional legroom. The chassis was so strong, that Mercedes-Benz used a pillar-less design that gave a very stately and elegant appearance with all four windows lowered. When it was new, the 300d cost three times that of a similar Cadillac, showing this was a serious automobile reserved for the wealthiest of clientele.The chassis design was in line with contemporary Mercedes-Benz design, to include independent front and swing-axle rear suspension. The swing axle was well proven but it did have some drawbacks, mainly a propensity to suddenly change camber under load and upset the handling. The solution, introduced on the 300d, was a unique self-leveling device consisting of electric motors actuating jackscrews that moved an extra pair of torsion bars. Unlike later systems, the 300d’s leveling system was driver controllable. From the 300d, all U.S.A. delivered cars were fitted...