Just to double check - the color on your GT and Mustang GT is "Tungesten Silver", not "Tungsten Grey". Tungsten grey is too purplish, and Satin Silver is too grey - I'm looking for that, as you put it, metallic shine.
Ford introduced the new Mustang GT concept with the idea of making something very similar. But then the Idea of the GT500 came along. Everyone knows the GT500 has to be a "mean" car so they kept the aggressive fascia for the GT500 and gave the GT a more subtle look. This way the GT500 is a notch above the GT not only in performance, but visuals as well.
If I buy a mustang GT (Thats if I cannot afford the projected Boss ) I will buy a GT500 front fascia to bring that aggressive look that ALL mustang GT's should have. (The V6's can have the "plain" look )