Just as a counterpoint though:
This car, like any other, is tuned from the factory to be biased toward understeer, which is considered the less frightening option for most drivers--that is, the lowest common denominator.
SVT took the approach, rather than plus-sizing the rear, of downsizing the front bar to tune out a teency bit of that understeer.
I would say that on an SE, a bigger rear bar is a fairly conservative approach, as it should reduce lean in the corners, and tune out some understeer, without affecting overall ride quality in "level cruise." Aren't there lots of SVT's running the Aussi bar? If anyone's going to have oversteer problems, it should be them. On an SE, it would be less of a problem, due to the larger front bar. Or if there's still a concern, how about the BAT bar?
Obviously, you can go too stiff on a rear bar, but I think (though I don't know from experience) the the bars available to us offer a small enough shift in under/over balance not to be dangerous.
Of course, I agree that tires ought to be number one.
