first of all you need to be comfortable with your car, you will be able to better feel what the car is capable of. The only way to do this is practice.
Here is what will keep you on the road, I live by this:
If you can't see the complete corner and road ahead, don't speed through it.
If you don't know the road, learn it first (pavement type, potholes, etc.)
If there's not enough room for your car to completely spin around and still be on pavement, don't speed through it. (I don't take any corner too fast if
there is ANY possibility of hitting ANYTHING in a spin out)
If your back end starts slipping don't go for the natural reaction of brakes, stay on the gas.
I also think about my cars balance at all times, you must respect and fear this car.
I suggest taking your car to an empty parking lot to learn YOUR MR2's characteristics before ANY exertions on streets. For example, my latest MKII has a tendency to understeer, which to me is worse than oversteer... So If I had gone through a corner on the streets too fast before testing it's character, I may have ended up against a curb because I'm not use to understeer and controlling it. (although I learned to use the brakes quick, haha) suspension mods and tire/rim combos have great impact on how the car behaves.