sentences:  US models include a choice of V6 and V8 (SS only) engines, Tremec TR-6060 6-speed manual or Hydra-Matic 6L50 6-speed automatic transmission, and went on sale in 2011–12.Japanese models include a choice of four base (silver ice metallic, black, victory red, summit white) and two premium (rally yellow, inferno orange metallic) body colours.They went on sale on 15 July 2011.