The Audi Sportback Concept is likely an early glimpse at an Audi A7 that will look to cash in on the growing "four-door coupe" fascination. Like the Mercedes-Benz CLS, which is based on that automaker's middle-child E-Class sedan, the A7 will supposedly share underpinnings with the Audi A6. But unlike the CLS, which is very much a sedan, the Sportback Concept is technically a hatchback. The concept car is powered by a 225-horsepower 3.0-liter V6 direct-injection diesel that meets both 50-state and the 2014 European Union emissions standards, and that Audi claims will deliver highway fuel mileage in excess of 40 mpg. What's the likelihood of seeing concept car's big 21-inch wheels on a production version? About the same as seeing its race-car-style ceramic brakes make the cut. Inside, the Sportback's gorgeous passenger cabin is, at the same time, more opulent, more minimalist and more modern than the excellent Audi interiors of today.