Unfortunately, the result doesn't look quite like the actual car we were shown. Starting at the front, the rendering actually looks a lot more like the late departed XLR roadster than the ATS. The styling buck we saw had a taller nose in keeping with modern pedestrian safety standards. Additionally, the grille of the ATS is of the same style as seen on the current CTS and SRX as opposed the egg-crate pattern shown on the illustration. One element that is accurate is drawing's headlights, which stretched well back along the top edge of the fender on the production-intent model we saw.
At the back, the ATS has a longer rear overhang and deck with proportions more like the current CTS sedan. The truncated rear end of the illustrations is completely wrong and the sharply creased edges all around are more reminiscent of early "Art and Science" Cadillac models like the XLR and first-gen CTS. The actual car has the same slightly softened look of the current CTS. A tip of the hat to Pierce!
[Source: Motor Trend]