Some cars become famous because of how they look. The Mercedes-Benz 300 SL became an icon because of what was underneath. For October’s Unique Car of the Month, we’re going back to 1954 and one of the most important sports cars ever put on the road: the Mercedes-Benz 300 SL Gullwing. Its story began in motorsport. Mercedes-Benz’s W 194 racing car scored major victories in 1952, including at Le Mans and the Carrera Panamericana. When the road-going 300 SL arrived in New York two years later, much of that competition-bred thinking came with it. Even the feature that made the car famous was rooted in engineering. The lightweight tubular spaceframe sat too high along the sides for conventional doors, leading Mercedes-Benz to hinge them at the roof. The solution became the unmistakable Gullwing silhouette. Under the hood, things were just as significant. Its 3.0-liter inline-six featured direct gasoline injection, helping produce 215 horsepower and giving the 300 SL a top speed of up ...