always rotate
transform.Rotate(new Vector3(0, 0, 1),Space.World);
transform.Rotate(new Vector3(0, 0, 0.2f);
rotation
Quaternion rotationC = objectC.localRotation;
Vector3 rotC = rotationC.eulerAngles;
rotC.z = -heading;
???
gameObject.transform.Rotate(new Vector3(0,1,0),Input.GetAxis("Horizontal");