Official GT site has a list of PC wallpapers — Ferrari is on it.

At the official (and officially Japanese) Gran Turismo HD website there’s a list of wallpapers for PC users to download featuring cars from the Premium and Classic modes of the PS3 real driving simulator.

One of those tasty inclusions to the list is the Ferrari 599GB ’06 — though the wallpaper image for the car isn’t there on the website currently, sorry gearheads. We’ll have more on the lineup for Gran Turismo HD (both the Classic and Premium modes) as the IV-drip of GT’s automotive roster leaks slowly until GT:HD’s launch.
Source: gametab.com