Allegedly, every other GT500 mule we've seen since May were refreshed GT350 mules mistaken for the Mac Daddy.Despite this GT500 prototype not displaying any of the Mustang's 2018 mid-cycle updates, it's believed production versions will arrive with a supercharged 5.2-liter V8 potentially kicking out 700+ horsepower, however, it's unclear if the motor will be of the flat-plane crank variety.If you look closely there also seems to be a half-cage or a cross-bar lurking behind the driver, lending credit to the idea that Ford could be looking to perform an exorcism in Auburn Hills.Take the rumors with a grain of salt, this is now the third potential engine we've heard bandied about after talk of both a twin-turbo 5.2-liter and a 7.0-liter V8 have made the rounds in recent months.It's also believed the GT500 will make use of a DCT transmission, along with 20-inch wheels and special styling.Expect to see the 2019 GT500 show up sometime next year.