I think that the rules for the Monte Carlo series should be somewhat loose concerning wheel/tire width/track width. There are a lot of unknowns with the rally track for car size, width and so on. A small car with little wheels/tires may well outrun a larger car with wide tires. Keeping things open for the first races will allow for experimentation to find out what works. The balance between tire grip for the straights versus the cars sliding in the handbrake turns will be interesting.
Russell