Detroit, Michigan - An atomic sunrise came to mind as the Nissan Sport Sedan Concept came into focus on its stand at the 2014 Detroit auto show. Sure, the orange hue on this car is visually radioactive, but also this Nissan concept represents a burst of creative energy that that will define a new design vocabulary for Nissan.

Concept cars from Japan have generally been pretty self-effacing over the years, yet Nissan itself has been recently undergoing an overdue design renaissance. First came the Nissan Resonance at the 2013 Detroit auto show, then the Nissan Friend-ME at the 2013 Shanghai auto show, and now the Nissan Sport Sedan Concept here at the 2014 Detroit auto show. Like most of the work from the studios overseen by Nissan/Infiniti design director Shiro Nakamura, the result here is not exactly beautiful; it's more of a high-concept look than enduring beauty.

This is all the more surprising because we think the Nissan Sport Sedan Concept is a concept in name only. If you peel back the concept label, we think you'll find out soon that this is a production car - the 2015 Nisan Maxima, to be exact.

Yes, we've got the big grille now

Nakmura says, "Nissan's design language is our brand promise - 'Innovation and excitement for everyone'- rendered in metal." The strongest bit of this promise can be found in the "V-motion" grille, a response to the oversize grille that designer Walter de Silva first developed for Audi and which has since become a widely imitated fashion.

As Nissan describes it, the V-motion design gesture flows from the grille to the hood and then completes itself in the broad windshield. The grille is complemented by a deep front fascia that incorporates heavily modeled ducts. Wild boomerang-style LED headlights complete the look.

We're told that the V-motion grille will find its way to both Nissan cars and trucks in the future.

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Long, low silhouette

"Our new design direction mirrors the strength, power and capabilities of engineering and innovation that serve as the foundation of every Nissan vehicle," Nakamura says. We think you can find much of this in Nissan Sport Sedan Concept's silhouette, which seems refreshingly long and low to us.

The hood line is certainly lower than what we have seen from European carmakers, which must meet new governmental regulations for pedestrian impact protection in their home countries. The front and rear overhangs are short, plus the ride height is low, so the car looks very long, even though the car measures 191.7 inches overall on a wheelbase of 111.2 inches.

The fender forms also have a fully sculptured look, and when you combine this with the big 21-inch cast-aluminum wheels with 275/30R21 tires, the car takes on a look that is muscular. Nissan says, "The resulting look imparts a sporty and athletic strength, rather than brute, aggressive force."

Look, my roof is floating

Just as with the Resonance and Friend-ME concept cars, the Sport Sedan has what Nissan describes as a "floating roof." It's an interesting expression of elegance that clearly will become a signature of forthcoming Nissans.

Nakamura comments, "[I]t makes it seem as if there are no pillars at all, enhancing the sense of athleticism and sportiness." He says this roof treatment balances the heaviness of the lower body, notably the sculptured line along the rocker sill that seems to connect the front and rear wheels.

We like the roof because it promises lightness and openness. It reminds us that we're tired of squat lids with narrow windows, which make cars look like assault vehicles.

Boomerangs from Japan

Once you get to the back of the car, you begin to realize that the Sport Sedan is somehow very Japanese, even thought it was initially conceived at Nissan Design America in San Diego, California, and then developed at Nissan Global Design Center in Atsugi, Japan. There's clearly a lot going on back here.

Of course, you have to kind of expect this as all the shapes try to come to some kind of resolution. You find yourself seeing the boomerang lights again as if to find something to blame for all the surface excitement. At the same time, the boomerangs also accentuate the car's width, although it technically measures only the customary 75.3 inches.

Quilted for your protection

When you look into the interior of the Nissan Sport Sedan Concept, you're able to tell that this car hasn't strayed too far from the platform of the Nissan Altima, from which so much of the Nissan lineup derives. There's lots of chrome on the dash and the leather upholstered seats have fancy diamond stitching.

Of course, if you stop there, you miss the fact that you have here a two-tone color treatment, which is a real innovation at Nissan. Monochromatic black interiors are the signature of performance, but Nissan has clung to this look far longer than other carmakers, and it has sometimes betrayed itself by tolerating color values that are less than the best. For Nissan, a two-tone interior is real innovation.

A big statement from Japan

This concept sedan isn't exactly beautiful, but it looks like it's from Japan, and we like that a lot. Japanese carmakers have almost always embraced derivative shapes and styles in an effort to keep from alienating potential customers, but apparently those days are done at Nissan.

Most important, the Nissan Sport Sedan Concept is an expression of excellence. This also is a refreshing change from Japan, and we're glad to see Nissan's enthusiasm for modernity here.

And in case you're wondering, the name of the radioactive color is "Strad Amber." It's meant to recall the finish of Stradivarius violins, which (Nissan says) are capable of a broad range of musical tones, from vibrant intensity to simple stillness. A base of gold paint is overlaid with an orange-amber topcoat, and the overall effect is that of a candy-color finish.

We can't wait until we drive the 2015 Nissan Maxima in this color.