Kia says the K900's design is based on a concept called "Gravity of Prestige," which certainly has resulted in a restrained, tasteful sedan without gimmicks. Even if the sportback Stinger positioned below the K900 looks good, it's a far more aggressive and whimsical design than what we see in these images. Kia mentions the new "Quadric Pattern" front grille on the K900 as having 176 "jewel-like" cells, which create an illusion of energy much like the spindle grille on the Lexus LF-1 Limitless concept; the headlights in turn are inspired by "the trajectory of light," and are called Duplex Comet lights.
These teaser images aren't far from the finished product, as Kia says the K900 will already go on sale on the second quarter of 2018 in selected markets. So a full reveal is surely happening soon. It could be a good candidate for the New York Auto Show, since it's both a U.S. location that would make sense for a car partly designed in America, and it's one of the last big shows before the second quarter of 2018.