I dont know about that Scrabby.. all the cars that i watched go straight on instead of making the corners this weekend were FWD, When they made a mistake and locked up, they could not turn, Where as alot of the RWD's that were making mistakes, i noticed just scandinavian flicked their way around the corners out of trouble. When it comes to rally's its not as simple as front or rear, Very different to track racing.
All i can suggest is get something that you can get things like mirrors and engine parts on the cheap, because they will need replacing!
Chatting to one of the teams running in an Audi Quattro this weekend they budget themselves a grand a race for the entry fee(s), fuel, transport and normal parts wear and tear. So just think about your budgets and cost's AFTER purchase, instead of how much it costs to start with.