9. 2005 Ford Mustang GT-R Concept
The 2005 Mustang GTR was soon forgotten, but its legacy lives on in numerous modern Mustangs. First, it was a prototype of a track-ready Mustang with fantastic design and cool race tech. Second, it featured a then-new 5.0-liter Cammer crate V8 with 440 hp, which was later available to the general public.
Third, it showcased many Ford Performance parts and components (via CJ Pony Parts) that can still be bought today and are an integral part of building a modern Mustang for a track day.