When i first bought my 33 i was going down the highway 110 klms/hr so i decided to do a little test i,brake fairly firm and pulled up into the brake down lane on ever so gradual left hand sweeper,The rear end promptly felt like it was a big boat with body roll borderline on about to start to drift.(had coil overs as the only suspension mods at the time)
So anyway i went and bought myself a pair of strut braces front and rear.The problem was much less noticeable,and felt like i had gained a shit load more controll over the beast.
I think that the initial brakeing was causeing the car to dip the front and let the left inside rear tyre lift causing the uneven trye contact on the road,thus making the car feel unstable.
M2C.....
P.S.If the car has bodge bushes with heaps of movement,you wont get the response from the car your after.Likewise if you take it to the track without a good suspension setup.
I have just driven a new SS 6.0L,and while the power is there.The handeling has left a bit to be desired for.I think that the only thing that it has going for it,from a track car point of veiw,is the re040 potenza's.Still what can you expect from a brand new 2006 model car.
With coil overs,good tyres and some fetteling it could be much better though.