This is my 2007 Redfire Metallic Mustang GT/ CS. I traded in my 02 Black GT for this Mustang and I cannot believe the improvement in performance. I have only upgraded the Shaker 500 sound system at this time with changing out the rear deck 5x7's and also adding 2/12" Kicker CVR Subs with a JBL 1200W Amp. I have also ordered 8" Kicker shallow mount subs with an additional Kicker 250.1 amp. Future plans on changing out the cold air intake/tuner. Has anyone done this on the CS model? There are so many combo packages of cold air/tuner's that it is hard to make a decision. The original California Special was built in 1968 and only 4118 were made, can you imagine what they are worth now.