my take on it...
i dont think its massive rear grip. its more the timing of the counter, how much angle his steering HAS, and how aggressively he is tossing it in. He also brakes in all of them i believe. he is basically throwing a 180 but throws it soft enough (while throwing it hard), with quick (early) countersteering. he catches it with the brake i think, and then dumps on the throttle. as the car stops its backward momentum while sliding to the side, it instantly starts going back forward and the car 'drives' out of the extreme angle.
think of being in your car, stopped, and turning wheel full over. now drop to clutch at like 4k and do a burnout. itll turn to the side. now instead of starting at a stop, you have to throw the car into a stop in the Y (forward/backward) momentum while keeping some X axis (sideways) momentum. The rest is all timing and throttle/steering to come out of it in the same direction or to transition.
its not impossible in theory but SHIT, its VERY insane to do.