In my experience, a car never ONLY understeers, nor does one ONLY oversteer. Even a "perfectly balanced" car will either understeer or oversteer depending on the situation.
Oversteer is much, much harder to control, especially for those who do not have much exposure to its ugliness. Therefore, the OEM's tend calibrate the chassis so that it is almost impossible to get into oversteer. This means the car will almost always push, sometimes a lot.
My definition of a "balanced" car is one that oversteers as often as it understeers. On average, it is balanced. This does mean that in certain circumstances, it will oversteer, sometimes A LOT (i.e. spin). It is then up to the skill of the driver to avoid creating the oversteer-inducing circumstances or to handle it if it happens. Sporty cars, like ours, generally are calibrated more toward "balanced", away from "always understeers".
My GTI is bone stock, and it normally pushes, sometimes badly. After a couple of track days, I was searching for the fattest rear bar on the planet. However, I changed my mind after a couple of ass-puckering incidents. Both were similar circumstances, but on different tracks. These were fast, right-left transitions, one was in the wet. I think what went wrong is that I somehow lifted off the gas just prior the transition, and that is a big no-no in an FWD car. I remember thinking Whoa! This car CAN oversteer!
So now my thinking is more about how to reduce understeer by using a little trail braking or carrying more speed in the first half of the corner as opposed to getting that fat bar.
