A thousand horsepower of ANYTHING and the car is pretty much drifting you you're not doing much but keeping from a constant spin...like you said, it's hard to control and unpredictable!
Fantaman: It's true: you can drift with an automatic (tho i prefer manuals) in GT3, specially cuz the gear you're in can be held, even if it's auto (just hold down your up or downshift [R1 or R2 or whatever] as you brake & drift...the car will not hop out of gear as long as you hold this button down. My apologies if you already knew this.