They must of changed the way it distributes it's power on the later Scoob then. My Scoob & my Evo will spin all four in the snow getting up my drive way. Once the fronts start to spin like the one in the vid my rears kick in to. No need to read up on it I do it for fun in the wet. Maybe it's an rpm controlled diff locking thing? Think I will go read up a bit.