Lemme be the first to say...they have NOT fixed this on the '13's. 2013 v6 Performance Package here. Creaking shocks since 1000 miles. Dealer has told me twice it's new car sounds. BS!! I will be showing up at 7am tomorrow, and demanding something be done. At 10k miles now and creaking just as bad as ever.
Go to Leif Johnson and talk with service advisor Paul Ward and also ask for technician named Rudy to look at it. These two guys got my 13 PP fixed right up, no questions asked, without even a test drive. They're aware of the TSB and shouldn't hassle you. Tell Paul Aaron with the silver 13 model recommended talking to him.