There once was a time when coupes were coupes and sedans were sedans. But just like hardtop convertibles have blurred the line between coupe and cabrio, and crossovers between wagon and truck, a new breed of four-door coupes has emerged to create a new type of automobile. No car-exporting country has embraced this new segment quite as emphatically as Germany. And Germany being Germany, of course, they couldn't help but create high-powered, high-performance versions of these fastback four-doors, either.

We start with the Mercedes-Benz CLS63 AMG. The Affalterbach fastback has ditched the old 6.3 for a new 5.5-liter twin-turbo V8 producing 518 horsepower in stock form or nearly 550 with the optional Performance Package for a 0-60 time of less than four seconds. Make no mistake about it: that's supercar territory. Only in the CLS, you can also bring your best friends along for the ride. While the first CLS may have been a more dramatic design, the second-gen model cuts a more muscular profile. If you need more space, there's a Shooting Brake version, and for those for whom the $115k sticker price is too high, there's a new CLA45 AMG on its way, too.

Next up is Audi, which has tackled the segment with two models: the A5 Sportback and the A7. While the former isn't available in four-door form in the USA, the latter is, and to make the prospect that much sweeter, it's available in S7 spec as well. The slant-roofed S7 is a sleeker take on the S8 sedan, and visually stretches lengthwise for a mile and a half. Power comes from a 4.0-liter twin-turbo V8 with 414 horsepower for a 4.7-second 0-60 time that is less powerful and slower than the Benz, but at $75,000 it's also considerable less expensive. A potential RS version could stand to close those gap, though, with 560 horsepower.

Setting aside its oddly-proportioned X6 slantback crossover and 5 Series Gran Turismo wagon, BMW was the most recent the join the game with the new 6 Series Gran Coupe. Adding a couple of doors to the existing 6, the new Bimmer is less a fastback sedan and more a four-door coupe than its competitors. And just like the 6 Series coupe became the M6 coupe, so has the Gran Coupe become the M6 Gran Coupe. Like its rivals, the M6 Gran Coupe is powered by a twin-turbo V8 (4.4 liters in this case) with 560 horsepower on tap to hustle it to 62 mph in 4.2 seconds. The top speed, like in most German cars, is similarly limited to 155 mph.

Porsche's Panamera may not have the sexy roofline of the Mercedes, the Audi or the BMW, but it is certainly deserving of the four-door coupe designation. Styling aside, the Panamera is rated as one of the finest-handling four-doors on the market, and its interior is a snug but beautiful place to spend a road trip. Zuffenhausen offers a range of engines in the Panamera, starting with a 3.6-liter V6 and ranging all the way up to a 4.8-liter turbo V8 with as much as 550 in the top-of-the-line Panamera Turbo S. That'll take you to 60 in three and a half seconds, but will set you back a princely $175,000, making it the most expensive proposition in this segment and on this list.

If all these high-performance four-door coupes blow your budget right out of the water, consider the Volkswagen CC. Where the Mercedes, Audi, BMW and Porsche count their sticker prices in six figures, the VW counts its in five. The VW recently underwent a facelift. But instead of twin-turbo V8s, the CC offers a turbo four or a V6, with 200 horsepower or 280, with a manual or an automatic and driving the front wheels or all four. With a seven-second 0-60 time, it won't be out-dragging any of its higher-priced and -powered compatriots, but it can still look the part (especially in R-Line spec), and with prices in the $30-40,000 range, is a far more viable option for more buyers.

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