Mercedes-Benz pioneered the modern four-door-coupe segment with the original CLS nearly a dozen years ago. Now, the redesigned third-generation CLS continues to rely on the same recipe: a sleek, low-slung sport sedan with some compromised visibility and cabin access. Fit and finish is excellent, but the controls are complicated. The CLS seats five people. The base engine is a 362-hp turbocharged six-cylinder engine, marking Mercedes-Benz's return to a straight, inline six-cylinder. Basic driver assist systems are standard, including blind spot warning, active braking, and a driver-attention monitor. Consumers will have to pay for the optional package that includes active steering and adaptive cruise control.