This is interesting, Ford Authority seems to think that this might not be a GT500. Instead they think it could be a test mule specifically to test the Mustang's suspension, brakes, and other elements. Not the Predator V8 powerplant.
There are certainly some things about this particular vehicle that suggest it could be a GT500 mule – including its wide track, S550 GT500-derived carbon fiber wheels, dive planes, quad-tip exhaust, big brakes, and Michelin tires. Additionally, the S550 GT500 started life as a GT-based mule, which is also the case here.
On the flip side, the hood on this mule is not raised to make room for the supercharger on the Ford 5.2L V8 Predator engine, which would be a notable omission, as it’s expected to power the next-gen model. Additionally, the front end doesn’t have any additional air intake space that would be needed to provide the cooling for that powerplant. However, since this is a mule and not an integrated prototype, these things aren’t necessarily unusual by any means, as Ford could simply be testing parts of the new GT500 – not the entire package.
Instead, it could be a chassis mule designed to test the car’s suspension, brakes, and other elements, though not the Predator powerplant. Thus, it’s somewhat unclear what, exactly, we’re looking at here – whether it be the new GT500, Mach 1, Boss 302, or something else entirely – but one thing is for certain – we’ll be seeing more production-ready versions of this model in the near future, as well as a gradual shedding of camouflage, so stay tuned for future sightings!