While the Dark Horse is said to effectively replace the S550's
Mach 1 variant, which itself took over in principle from the
previous GT350 as the sweet spot of the track-biased naturally aspirated Mustang
experience, the Dark Horse's price would suggest that a
a potential GT500 would be ridiculously priced.
We only say so because a fully loaded S650 Dark Horse is costlier than an S550 GT500.