Ford recently released this info about the 2013 Mustang GT/CS California Special model.
-Black Billet Grille with Tri-Bar Pony Badge
-GT/CS Side Stripes and "5.0" fender badge
-Hood Stripes
-Lower Fascia with fog lamps and air splitter
-19"x8.5" Black Painted / Machined-Aluminum Wheels
-Decklid Badge
-hood vents
-Door-panel inserts with bright Pony badge
-Front and Rear Leather Seats with Miko Suede Inserts and GT/CS logo
-Premium carpeted front floor mats with embroidered GT/CS logo
-Rear Diffuser Style Lower Fascia
-Pedestal Spoiler
-Side Scoops