Beeping I think is normal, and hard intrusion is normal(apparently), since the GX case in particular is that its not intruding hard enough to correct the slide.
I think the car itself is probably doing as expected, and I kinda agree with CR that its more of a ESP calibration side of things. GX is a 4-Runner based SUV, truck platform with real off-road capability, as a result, high ground clearance is a design choice and CG height is a result of it. Lift-off oversteer is probably the order of things with that design. But if CR does the same test for all the cars and this ends up being the worse off, then I suppose it has merit for the do-not-buy rating.
University of Toronto Formula SAE Alumni 2003-2007
Formula Student Championship 2003, 2005, 2006
www.fsae.utoronto.ca