i remember someone weighing a new 08 w/ nav at just about 3800.
if Ford produces a GT500 under 4000 lbs with 750 HP, beefy IRS, magnetic ride, 10-speed auto (optional) and it can actually hook, then they may get my attention.
is that unrealistic to expect? I don't think so.
If Ford produces a GT500 with the specs you listed, they would have my full attention.