C# CarDamage script: Array index is out of range error.

So the problem is that I have an car damage script, which deforms mesh on collision. It works but it keeps giving me this error and I don't understand what's wrong it. So if someone could point me on right direction.

ERROR:

IndexOutOfRangeException: Array index is out of range. CarDamage2.OnCollisionEnter (UnityEngine.Collision collision) (at Assets/Scripts/CarDamage2.cs:44)

SCRIPT:

 using UnityEngine;
 using System.Collections;
 
 public class CarDamage2 : MonoBehaviour 
 {
     public float maxMoveDelta = 1.0f; // maximum distance one vertice moves per explosion (in meters)
     public float maxCollisionStrength = 50.0f;
     public float YforceDamp = 0.1f; // 0.0 - 1.0
     public float demolutionRange = 0.5f;
     public float impactDirManipulator = 0.0f;
     public MeshFilter[] optionalMeshList;
     
     private MeshFilter[] meshfilters;
     private float sqrDemRange;
 
     public void Start()
     {
         //maxMoveDelta = Mathf.Clamp01(maxMoveDelta);
        
         
         if(optionalMeshList.Length>0)
             meshfilters = optionalMeshList;
         else
             meshfilters = GetComponentsInChildren<MeshFilter>();
             
         sqrDemRange = demolutionRange*demolutionRange;
             
         /* doesnt work, strange physic behaviour
         for(int j=0; j<meshfilters.Length; ++j)
         {
                if(!meshfilters[j].transform.collider)
                 {
                 meshfilters[j].gameObject.AddComponent<BoxCollider>();        
                 meshfilters[j].transform.collider.isTrigger = true;    
             }
         }*/
     }
     
     public void OnCollisionEnter( Collision collision ) 
     {
         Vector3 colRelVel = collision.relativeVelocity;
         colRelVel.y *= YforceDamp;
         
         Vector3 colPointToMe = transform.position - collision.contacts[0].point;
 
         // Dot = angle to collision point, frontal = highest damage, strip = lowest damage
         float colStrength = colRelVel.magnitude * Vector3.Dot(collision.contacts[0].normal, colPointToMe.normalized);
 
         OnMeshForce( collision.contacts[0].point, Mathf.Clamp01(colStrength/maxCollisionStrength) );
         Debug.DrawLine(collision.contacts[0].point, transform.position, Color.red);
         //Debug.Break();
     }
     
     // if called by SendMessage(), we only have 1 param
     public void OnMeshForce( Vector4 originPosAndForce )
     {
         OnMeshForce( (Vector3)originPosAndForce, originPosAndForce.w );
     }
 
     public void OnMeshForce( Vector3 originPos, float force )
     {
         // force should be between 0.0 and 1.0
         force = Mathf.Clamp01(force);
         
         for(int j=0; j<meshfilters.Length; ++j)
         {
             Vector3 [] verts = meshfilters[j].mesh.vertices;
 
             for (int i=0;i<verts.Length;++i)
             {
                 Vector3 scaledVert = Vector3.Scale( verts[i], transform.localScale );                        
                 Vector3 vertWorldPos = meshfilters[j].transform.position + (meshfilters[j].transform.rotation * scaledVert);
                 Vector3 originToMeDir = vertWorldPos - originPos;
                 Vector3 flatVertToCenterDir = transform.position - vertWorldPos;
                 flatVertToCenterDir.y = 0.0f;
                    
                 // 0.5 - 1 => 45° to 0°  / current vertice is nearer to exploPos than center of bounds
                 if( originToMeDir.sqrMagnitude < sqrDemRange ) //dot > 0.8f )
                 {
                     float dist = Mathf.Clamp01(originToMeDir.sqrMagnitude/sqrDemRange);
                     float moveDelta = force * (1.0f-dist) * maxMoveDelta;
 
                     Vector3 moveDir = Vector3.Slerp(originToMeDir, flatVertToCenterDir, impactDirManipulator).normalized * moveDelta;
 
                     verts[i] += Quaternion.Inverse(transform.rotation)*moveDir;
 
         
                     //Debug.DrawRay(vertWorldPos, moveDir, Color.red);
                     //Debug.DrawLine(vertWorldPos, transform.position, Color.green);
                     ///Debug.Break();
                 }
 
             }
        
             meshfilters[j].mesh.vertices = verts;
             meshfilters[j].mesh.RecalculateBounds();
         }
     } 
 }

ERROR LINE FROM CODE:

 Vector3 colPointToMe = transform.position - collision.contacts[0].point;