What setting do you use on the rears?

Mine only had two settings. I used the first setting so it wasnt ultra stiff. I love the way the car handles now.

No issues with oversteer?

None. I even didnt have anti slip or VDC and drove in the rain all day last Saturday. This was some spirited driving as well. I was actually very impressed with how planted the car is and the responsiveness of the steering. I worried that it may be too responsive, since it was my first distant drive since the install. But to my surprise it was awesome. The fronts are also set to medium.