ok...so i think i've realized that S197 is the 05 mustang whereas S195 was the older style. But where do these names come from what does the S197 signify. I know...dumb newbie question, but i'm just curious. I tried searching, but couldn't find an answer.
197 is the project number. It has no real significance other than being a sequential number (EVERY project that anyone at ford dreams up gets a number, only a few ever come to fruition. Thats why SN95 seems to be directly followed by S197.) N stands for North America. Ford used to include the intended market in the project code.