This was taken from wiki:
SEMA Show 2007 demo
The North American version of Gran Turismo 5 Prologue demo was unveiled at Sony's booth during the 2007 SEMA Show in Las Vegas, Nevada.[48]
Compared with the Japanese demo this new version had American cars (Dodge Viper GTS '02 and Ford Mustang V8 Coupe Premium '07) and tracks (Daytona International Speedway), these were included but not playable in the PSN demo.
An American tuner car, the Art Morrison Corvette '60 SEMA version 2006, was added to the selectable vehicles.[48] This vehicle was later added to the retail game with update "Spec II".
Was this on psn in the usa, or just for the sema show?