This quote from Autoblog.com should answer your question:
autoblog.com said:It's a nicely proportioned thing, too. It's roughly the same size as a C-Class, and the four-door coupe language works quite well here in a smaller package. Mercedes designers have done a fantastic job with this sleek design on the larger CLS, and it's arguably even better-looking here on this little guy. You really need to see the CLA in person to realize just how good it looks.