The ROUSH Stage 3 package for the Mustang GT is the ‘halo’ over the ROUSH Performance shop. This package incorporates appearance upgrades of Stage 1, suspension and brake upgrades of Stage 2 and adds a supercharger to the base V8. In 2010-2012 a ROUSH 2300 ROUSHcharger boosted horsepower to 540 on both the 4.6L (2010) and 5.0L V8s. In 2013 the ROUSHcharger featured Eaton’s TVS (Twin Vortices Series) technology which made it more efficient and increased its rating to 565 hp. Power continued to increase in 2014 to 575 for the Stage 3 package.

2012 included two exclusive ROUSH Stage 3 packages. The Premier Edition (15 coupes/1 convertible) in collaboration with Sherwin-Williams offered 12 exclusive color choices, and Hyper Series (79 coupes/1 convertible) were black with seemingly unlimited accents in one of four exclusive colors: Mat it Mango, Gas it Green, Punch it Purple and Launch Lemon. Twenty vehicles in each color were produced.

In 2014 customers had more performance and track-focused options to choose from including an X-Brace and rear seat delete as well as the Ford Racing Aluminator engine which served as a base for Phase 2 (620 hp) and Phase 3 (675 hp) upgrade kits beyond the standard ROUSH Stage 3 package.