The force that causes the tires to slip isn't a force, but it's called momentum. Momentum describes a moving objects desire to resist a change in direction. When you drive, the car and everything inside the car has momentum. When you turn, the car WANTs to continue in it's straight path but the force of friction between the tires and the road, if high enough, causes the car to turn, but because of its desire to resist change in direction, the car leans and you feel like there is a force pushing you towards the outside of the corner when there isn't. That feeling is what people like to think of as centrifugal force. Now, if momentum is too great, then the tires break the force of traction and you slide. Better?