If history repeats itself, the ford GT 3.5 will end up in a mustang gt500/mach1 whatever it'll be called. You'll see. They are using the 3.5 ecoboost in f150, flex, Taurus, raptors, GT, the mustang is next.The EPA regs are the only reason for this. The demand for V8s in performance cars has not slowed, only the conditions that permit them to stay in the mainstream.
The sports coupe buyer is increasingly concerned with fuel economy, but it is still far down the list of reasons to buy.