You heard it right, 2016 Mustang Cal Special is coming back:
"There's a California Special Package being offered on the Mustang GT Premium with such touches as 19-inch black machined alloys, hood and side stripes, black spoiler, mirror and hood vents, dark taillamp accents, a front splitter, special grille and gas cap, strut tower brace and an interior decked out in black leather with suede inserts and red stitching."
See http://www.autoblog.com/2015/05/11/2016-ford-mustang-gets-new-packages-trim-and-hood-vent-turn-sig/
"There's a California Special Package being offered on the Mustang GT Premium with such touches as 19-inch black machined alloys, hood and side stripes, black spoiler, mirror and hood vents, dark taillamp accents, a front splitter, special grille and gas cap, strut tower brace and an interior decked out in black leather with suede inserts and red stitching."
See http://www.autoblog.com/2015/05/11/2016-ford-mustang-gets-new-packages-trim-and-hood-vent-turn-sig/