I'm currently in the restoration process of my 1979 Cobra and need a few pointers. My back glass needs replaced, but i don't want to spend the big bucks to have professional glass replacement. A friend of mine found a back glass from a 1989 mustang. Since they're both fox body styles, does it matter that one is ten years older? The only difference i can see would be the 89 having a rear defroster, but i can ignore that. Any ideas?