if you're implying that the GTR concept image is a photoshop of that opel photo, you're probably wrong. using the same method that was used to compare the original G35 and the refreshed version here, you can easily see that the two images are pretty different, even when resized. for one thing the perspective is different in both images - try emulating that in photoshop.. the reflections all around the body and the windows are different which reflect the surrounding environments of each photo. the lighting is perfect, as are the shadows in the GTR concept image. making all these edits isn't impossible, but EXTREMELY difficult and not worth a magazine graphic designer's time. creating it from scratch would be easier.

i'm not saying this GRT concept isn't a photoshop, it just isn't a photoshop of that opel photo. i've attached two composite images, one where the rear wheel sizes of the two images matches approximately, and one where the front passenger side fenders are lined up. you can clearly see the differences.