rc drift can be split into two 'classes'. 50/50 which basic 4wd like most rc touring cars,and counter steer which is still 4wd but the gearing(pulley wheels or gears)has been modified so the rear wheels spin faster than the front to enhance the rear wheel drive affect. 50/50 is nice and simple to set up and drive,counter is a little more tricky. it requires a very good understanding of the gearing and steering and suspension geometry of the chassis to get the cs working properly.
http://driftmission.com/
http://www.csjunkies.com/