Dayum, he gave that ittle car a workout, didn't he? I saw the paddle shifter, but what was that big handle for?
My quess is "E" brake >>> sure helps with the extreme drift.
Exactly what it is - you can see his digital gear indicator on the dash, throughout - most seems to be done in 2nd and even 1st gear. We had brakes like that, on the old sand buggies, one on each rear wheel, as "cutting" brakes, so you could stop at the top, pull one, and slide backwards, spinning on that wheel. It helps get into the drift, then countersteering keeps it going.
Lots of fun, unless you do it on accident...
Then, no fun at all...