If it was a sweeping left turn and you went into the right lane it sounded like you understeered, especially if you have bald Kumho MXs which are already pretty crappy in the rain with full tread.

If you put a larger rear sway bar on your car you might experience snap oversteer in the rain or wet conditions. That's not fun at all. Although I have the Comptech rear bar on my Civic and so far no snap oversteer, but I also drive more conservative in the rain.