In a front engined FWD car it seems under heavy braking the weight transfer is very apparent where it feels like the back end gets really light. In the MR2 under brakes it feels much more balanced and doesnt have that front end dive like most cars. Of course suspension has a lot to do with this too.

In a fwd car, weight distribution is around 65-35. When you hit the brakes I'm guessing the front tyres will experience something like 85% of total weight leading to that light rear end feeling. In an mr2 with 35-65 distribution, under brakes there will be something like 45% weight on the rear. This means stronger braking, less nose dive and less of that floating rear end feel.

I agree with others who state you need to find out the limit at the track or it could end in tears.
Depending on your set up will govern how you drive the car. Vinny's car was very touchy to drive. You need a lot of finesse to drive it well. If you lift it was facing the other direction before you knew it. I would not drive this car in anger on the street. Why? Just the set up of the springs/dampers plus the age and alignment of the car. Also ran a open diff.
Mine ran spring rates at R8kg/F4kg which made the car dive mid corner causing it to understeer then snap out making it a busy drive. Changed to R8kg/F7kg which settled the car a lot allowing far more control and management of snap oversteer. A lot was gained from shock settings which managed oversteer and settled the rear of the car under load (softer was better) but as others have stated the bias must be correct or it can be a handful.
Incar with 8/7, too much rear bias and a broken rear toe link. It was ok but under hard braking, if you tried to turn in under braking it snapped out.. http://www.youtube.com/watch?v=lhJJ6bcxbNw
Here is Adrian showing how its done in a NA. Nice driving mate. http://www.youtube.com/watch?v=i_Q0abo-iMY
Here is another great driver in a NA managing it quite well. http://www.youtube.com/watch?v=vqOu-EOn3Wc
So as many have stated, alignment, brake bias, also tyre pressures, spring/shock rates, test at the track, watch incar footage and lessons
Good luck mate
 
 

Gotta agree with the comment about coming from sportsbike to mr2, you really learn to pick your corner speed before entry and keep throttle even for rear traction. I'm still yet to experience snap overseer, although sometimes like mentioned before an unknown corner can tighten and the choice is either to grip it and bear it or induce a slight bit of oversteer if not too high speed. Maybe it's just me but I love driving my car in the wet, I think it stays quite composed, obviously don't push it too hard through corners but nothing like driving down the street a little sideways haha.

Btw I know what you mean about front end lift, I want to start tracking my car very shortly and have plans to cut a hole in the wall behind the radiator to redirect air through a vented hood over the windscreen. Should give a bit of f down force and increase cooling... Getting a water to air intercooler to which will benefit from this air flow also.

But yeah as said in previous comments just don't back off mid corner and have fun playing about, there's only one way to find out what driving style works best for you and your setup;)

be smooth, brake early (& brake enough), and commit.
 
whether you know it or not with an MR you're committed.... a late change of line or backing off mid corner isn't something they're forgiving of, so you might as well own the situation.

At the fulcrum MR2 day about a year ago my N/A SW20 was corner weighed and it was about 56 rear and 44 front. That's pretty different to 65 rear and 35 front adrian was talking about?

^I'd say a turbo would be a lot more rear weight biased than an N/A.  

65/35 is even more extreme than an Elise! 56/44 is really good, that's like F1 specs hehe

I was just taking a punt. I thought I remembered reading 60something / 30something but that was a while ago and I'm probably well off the mark. 56-44 does sound more reasonable. 
 
I don't think the turbo would be too different. All the turbo gear wouldn't weigh too much. But then again I may not be the right person to trust with this kind of info.

Turbo + intercooler would weigh a little bit. However from what I understand the E153 gearbox and axles weigh a fair bit more than the NA stuff. Seeing as this is directly over the rear wheels, 60/40 is probably accurate.
65/35 is more 911 territory.