Ford has been pretty tight-lipped about the new next generation pony car but some recent spy photos of the 2015 Mustang s550 prototype reveal the changes might not be as drastic as first thought. As you look at the photos which come courtesy of Mustang6G.com you will notice a definitive change in shape from the current model. Although this prototype looks like a 4×4 Mustang the new body panels and car cover throw you off. A few things we noticed are the highertaillights in the rear, lower roofline and a more aggressive stance with less junk in the trunk. Kind of reminds us of the Mustang Giugiaro Concept Ford had commissioned back in 2006.