These spy photos reveal what appears to be a new large sedan destined for Nissan's model-range - essentially a competitor for the Toyota Avalon - testing in the Southwest desert. This prototype is clearly based on the Japanese-market Nissan Teana, a large sedan that slots in just below the Nissan Fuga in Japan (the U.S. version of the Fuga is the Infiniti M35/M45).
The key here is that this prototype is left-hand drive (LHD). The Teana is only available in right-hand drive for the Japanese market, and its interior is an old-school design that has some older Buick overtones. This prototype has been changed to LHD, making it suitable for the U.S. market, and our interior shot shows that its dashboard has been redesigned to resemble the current models in Nissan's U.S. lineup.
This Teana-based prototype retains the Japanese-model's quirky styling, which combines the side-window design from the Infiniti M35/M45 with a Maxima-like front fascia and a rear end that mimics BMW's rump-hump found on the new 5- and 7-Series.
Judging from the extensive repackaging of the interior to left-hand drive, it appears that this car is being readied for the U.S. market. So why create such a car to slot in above the Maxima? Toyota has adopted a similar strategy with its Avalon, and it appears that Nissan is attempting a similar attack - adapting an up-market (Infiniti) platform to get a piece of the large, near-luxury-cruiser market.