Rear Sway Bar?

[RedRide]

OK........
A rear sway bar will firmly plant the rear end on the road and enable one to take corners faster with little body roll.

It goes without saying that if you push a car to the limits of you tire's grip you will kick the rear end out.

On reason maufactures build in understeer (eliminate a rear sway bar,etc) is to keep inexperienced drivers out of trouble.
An experienced driver knows the limitations of his car/ suspension/tires and does not push it past that point.

Having said that, a rear sway bar will reveal a bad tire's limitations. So, good tires will enable more of a rear sway bar's full potential.

BTW, an experienced driver is always more careful in the rain no matter what they are driving.

Personally, I felt rather unsafe driving the Yaris.
After installing the sway bar, I now feel much more safer and secure driving it in all situations.