private void s(WheelData d)
        {
            if (!d.isGrounded)
            {
                return;
            }

            Handles.DrawSphere(0,
                               d.hit.point,
                               Quaternion.identity,
                               .2f);
        }
        private void DrawCollider(WheelData coll)
        {
            if (coll.visual == null)
            {
                Transform visual = coll.transform.GetChild(0);

                if (visual != null)
                {
                    coll.visual = visual;
                    Debug.LogWarning(coll.gameObject.name + " Wheels where automatically set.");
                }
                else
                {
                    Debug.LogError(coll.gameObject.name + ": Visual not set for Wheel. Can't draw Collider.");
                    return;
                }
            }

            Vector3 origin               = coll.transform.position;
            Vector3 suspensionTarget     = origin - coll.transform.up * coll.suspension.Distance;
            Vector3 suspensionCompressed = suspensionTarget + coll.transform.up * coll.suspension.Compression;

            // Draw Start
            Handles.color = new Color(1f, .7f, 0f);
            drawHorizontalLine(origin, .15f);

            // Draw Suspesion Spring
            Handles.color = Color.red;
            Handles.DrawLine(
                origin,
                suspensionTarget
                );

            // Draw Suspension compression.
            Handles.color = Color.blue;
            Handles.DrawLine(
                origin,
                suspensionCompressed
                );

            // Draw Collider
            Handles.color = Color.green;
            Handles.DrawWireArc(
                suspensionCompressed + coll.visual.transform.right * coll.width / 2,
                coll.visual.right,
                Vector3.up,
                360.0f,
                coll.tireRadius
                );
            Handles.DrawWireArc(
                suspensionCompressed + -coll.visual.transform.right * coll.width / 2,
                coll.visual.right,
                Vector3.up,
                360.0f,
                coll.tireRadius
                );


            // Draw End
            Handles.color = new Color(1f, .7f, 0f);
            drawHorizontalLine(suspensionTarget, .15f);
        }