It seems this car need rear tire with more grip. But equipping simulation front and normal rear make this car really hard to drfit. Try using more front camber, maybe 8 for your setting. Personally, I use this:
New BMW 380Ci, with stage 3 turbo.
Tire: Simulation tire both
Suspension
-Spring Rate: 2.0 / 8.0
-Ride Height: 155/155
-Bound: 10 / 10
-Rebound: 10 / 10
-Camber: 6.5 / 1.5
-Toe: 0.00 / 0.20
-Stabilizers: 7 / 1
Using this setting I still wish I can increase rear tire grip more.
To control sideways behavior I use a combination of spring rate and camber value.