the V6 roush's has the same stuff they put on a V8 roush.
here's the breakdown of cars
Sport package- Mostly V6s and some V8. Mostly just a body kit
Stage 1-same as Sport but has a nicer wheel and tire package and cold air intake.
Stage 2- same as Stage 1 but has suspension upgrade.
Stage 3- same as Stage 2 but has a Roushcharger.
also there are a few other rare collector versions such as the 360R, 380R, Byod Codington, and the 440A. 360R and 380R were pretty close to the Stage 3 car. the Byod version came in 75 NA cars and 25 supercharged versions. The 440A is a 400hp supercharger 40th mustang. There is also a Jack Roush Sigunature series but not real sure about the specs. That pretty much covers 99-04 Roush's. Now, I have left out some things but this is the basics of each one.