This seems to increase as the cars speed increases, is there a way to subtract the cars speed changes from the turn speed?
I am sceptic about this statement. I dont see how the angle would increase with speed.
Besides that, i dont think that is what you need. You need to know the resistance to Inertia.
When the frontwheels are alligend with the cars angle, there is no squealing. When they differend a lot, it means the tires try to go a differend path then the car. Depending on the grip, they will squealing.
I think you have to compare the Sprite.angle with Sprite.Car.MovingAngle. Probaly have to abs it. How bigger the difference how more squealing should happen. Got to account for the ground/grip with a factor.