Mercedes-Benz's new compact CLA-class sedan, whether it be in base CLA250 or fire-breathing CLA45 AMG guise, is a serious little four-door. Although it might at first come across as something of a handbag—a stylish runabout for the fashion-conscious set—its sinuous curves and creases dress up a nicely competent front-drive–based chassis. Any further notions that the [.]