Roush added Sonic Blue and Gold to its color options for the 380R, which was also available in black with gold stripes, white with blue stripes, and red with white stripes. Only 200 380Rs were made in 2004. Stage 1, 2, and 3 Roushes were also available, along with the Roush Classic, of which 50 were produced.

To commemorate the 40th Anniversary of the Ford Mustang, Roush introduced a 400 hp limited production edition – the 440A. This 400hp Roush Mustang was limited to a 40 unit production. The 440A represented the final production of the “SN-95” Mustang at the Roush plant in Livonia, MI. The 440A achieved 400 hp by an aftermarket addition of the following automotive respiratory features: high flow air filter, smaller supercharger pulley and a high flow exhaust. The Roush 440A carried a 3 year 36,000 mile warranty. All 40 were sold through Brandon Ford in Tampa, Florida. There were 15 coupes and 25 convertibles built. The available colors were Dark Shadow Grey with Black stripes, Competition Orange with Black stripes, Yellow with Black stripes, Crimson Red with Briar Brown stripes, Redfire with Black or Briar Brown stripes, Sonic Blue with Gold stripes, and Black with Briar Brown stripes.

The Roush 440A package upgrade was available on coupe and convertible Mustangs and carried a package upgrade MSRP of $26,000.