Maybe you should take a look at Foxy's mates F1 car, I think it is 1.5 scale and it had some sweet breaks on all 4 wheels, Hydrolic by the looks of it, aparently 700bucks a set.
If your driving a 1/8 scale nitro buggy Truggy or on-road race car, that'll probably have disc breaks also, just not on the wheels but on the drive shaft.
Electrics break on the motor.I think.
Dragsters are using a parachut, anker, disc break set up.
Most noobs just use a wall to stop.[:@]