How to change ford logo on Nav to Snake?

I have a 2008 GT500 with the Navigation system in it, and when you first start up the car it shows the Ford Logo, I saw one on the internet that had a SVT Snake when they turned on the car. Has any one changed there start-up pic? (Or was that just internet magic) I do believe that the 2008's use a different Nav system than the 2009+ models. Any info on the subject would be appreciated....