I'm a Ford Mustang fan so I tired to come up with an overall theme for my design based on the GT500. I also tried to use as many of the custom options as possible for my criteria, since the whole point will be for you guys to make the most of the customization experience.
Okay here goes.
Back: Royal blue
Accent: Silver, or metallic
Signature Engraving: "Shelby GT500"
Case: Clear snap case
Memory: 32 GB
Power on message: "A Racing Legend"
Wallpaper: If possible, the Shelby Cobra emblem, black background on the silver logo
Sol Jax Headphones: Royal blue, to match.