The Only way I think a RWD RC Would Drift and Drift Connection is to Have a Servo with a Weighted Object on It..

So when the Car Turns , this Weight would Kick the Tail Out, and when Steering Straight would Return to a Nuetral Posistion..

Best advice I can offer on a $ per $ Basis.

An AWD Chassis.. Isolate 1:1 Scale drift thoughts from the 1:10 or 1:5 Scale thoughts
A Front Engined RC car with Rear Wheel Drive would Still need some major tuning to drift correctly and would cost a forutne to set up..