try to avoid using the electronic aids, what you need to do is put a race suspension on, they are automatically set to understeer, so go into the settings. this is what i would do,
make it about 8-10 spring setting, (both front and back should be equal for all of this), the lowest height setting, about 4-6 on the bound and 6-8 on the rebound, depending on the cars weight, i think its about 1300kg so make the camber 3.6, zero toe and then 7 on stabilizers. once you have done this go into weight balance. put the balance to 50 (if the car is still understeering) and then slowly add weight until you have the amount of oversteer that you want. and then add power and everything else and youre good to go.
with the limited slip though, you shouldnt need it, but if the car is oversteering too much when you lift off the gas, raise the deceleration number. i always put torque and acceleration at 60. if the car is understeering too much when you lift off the gas, lower the torque.
good luck, and remember that high speed stability is extremely important at the ring much more important than low-speed understeer.
