I think ive done about everything possible to my xr6 lol (apart from building a forged motor) and upgraded brakes (doing in next few weeks) but the best modification ive done so far is strengthening the rear end. Independent motorsport twin diff bush setup, Diff Tekniks 1400HP CV's and the Eaton Trutrac, completely transformed the car it feels as though its really getting the power down to the wheels now with no sloppyness