All-new models tend to have all-new problems and the Mercedes-Benz CLA 250 doesn’t avoid that generalization. Ranked least reliable in the large/luxury/luxury compact cars class, the CLA actually helped drag down the German automaker’s overall brand score. In fact, the redesigned S-Class also attributed to its decline as Mercedes was the only European brand to see a significant drop this year. The company’s best performers from a reliability standpoint were the E-Class sedan and GLK SUV.