Yes, it is the full GT4. This is the Japanese version.

Chapter 5 (Page 111) of the reference guide shows the Crossfire in a "berry" colour with references to it being based on the SLK320.

I quickly jumped into Arcade mode and selected a Sapphire Silver Blue coupe for a quick run around the Nurburgring. They have even correctly modelled the wing going up and down at various speeds!!!