4wd slotBack in September 2014, I got the chance to examine and test-drive pre-production examples of a number of Slot.it models - last week, finally, I managed to get my hands onOn its Audi R18 e-tron Slot.it has created a 4WD system which is truly unique and innovative. In the Slot.it system, a toothed belt provides power to the front axle through two micro pulleys which are coupled to the left wheels.