Technically drifting is oversteer. Which means that while turning, your ass end has lost traction and is making a wider radius turn than the front end. The rear wants to go strait, but the front wants to go around the turn. Drifting is also:
#1. Brake before corner
#2. slightly lose tracion
#3. accelerate during turn in RWD car (forces rear wheels to spin and thus push rear end forward, not following front stearing wheels)
In GTA there is no FWD/RWD/AWD. The handling dynamics of the cars are far too inconsisten to come to a conclusion for each. I think they're pretty much 4WD. I've noticed this because #1. I can drive forward with the front wheels while engaging e-brake/parking brake. and #2. I can also do burnouts with the rear wheels. this proves that both wheels are drive wheels, and that there is no FWD or RWD cars in LC, VC, or SA. The TVR-like Stinger i was referring to, was in LC. So, as far as "drifting" concerns me in any of the GTA games, GTA 1 is pretty much the only one. Unless you're taking a very sharp corner while accelerating, all you're doing is powersliding.