the 2010 mustang in turn looks much like the 2005-09 model, but all the body parts except for the roof are different. the rear turn signals of the 2005-2010 cars blink in a one-two-three sequence like the 1967-68 mercury cougar and 1964-66 ford thunderbird. power for the v8 rose to 315 hp. in 2011, the mustang received new engines, a 3.7-liter v6 base engine with 305 hp and a new 5.0-liter engine with 412 hp. power on the shelby gt500 rose to 550 hp and later to 662 hp in 2013. a boss 302 performance version powered by a 444 hp v8 was introduced for 2012.