MeshDeformation

using UnityEngine;

public class VehicleDamage : MonoBehaviour {

    public MeshFilter filter;
    private Mesh mesh;
    private Ray raycast;
    private RaycastHit hit;

    private void Start() {
        mesh = Instantiate<Mesh>(filter.sharedMesh);
        filter.mesh = mesh;
        mesh.Optimize();
    }

    private void OnCollisionEnter(Collision collision) {

        foreach(var contact in collision.contacts) {
            Deform(contact.point);
        }
    }

    private void Deform(Vector3 pos) {
        var verts = mesh.vertices;
        for(int i = 0; i < verts.Length; i++) {
            var scaledVert = Vector3.Scale(verts[i], transform.localScale);
            var vertWorldPos = filter.transform.position + filter.transform.rotation * scaledVert;
            var origin = vertWorldPos - pos;
            var flatVertToCenterDir = transform.position - vertWorldPos;
            flatVertToCenterDir.y = 0f;
            if(origin.sqrMagnitude < 0.7f * 0.7f) {
                var dist = Mathf.Clamp01(origin.sqrMagnitude / 0.7f * 0.7f);
                var moveDir = Vector3.Slerp(origin, flatVertToCenterDir, 1f).normalized;
                verts[i] += Quaternion.Inverse(transform.rotation) * moveDir;
            }
        }
        mesh.vertices = verts;
        mesh.RecalculateNormals();
    }
}