Custom skin wont show up

Ive made a custom skin and followed tutorials and it will show up in my mods but it wont show in the parts selector

 

I've found this to be useful: Skin Helper

 

Heres the code

 

This is the format to use for the materials.json as far as I know.

Example from the Coupe:

Code:

{
  "coupe.skin.SKINNAME" : {
    "name" : "coupe.skin.SKINNAME",
    "mapTo" : "coupe.skin.SKINNAME",
    "class" : "Material",
    "persistentId" : "c033f0bf-31d0-4a1b-9a91-595e8f6f69f6",
    "Stages": [
      {
        "ambientOcclusionMap": "/vehicles/coupe/coupe_main_ao.data.png",
        "baseColorMap": "/vehicles/coupe/coupe_main_b.color.png",
        "metallicMap": "/vehicles/coupe/coupe_main_m.data.png",
        "metallicFactor": 1,
        "roughnessFactor": 1,
        "normalMap": "vehicles/coupe/coupe_main_n.normal.png",
        "roughnessMap": "/vehicles/coupe/coupe_main_r.data.png",
        "useAnisotropic": true
      },
      {
        "ambientOcclusionMap": "/vehicles/coupe/coupe_main_ao.data.png",
        "useAnisotropic": true,
        "diffuseMapUseUV": 1,
        "clearCoatFactor": 1,
        "clearCoatRoughnessFactor":0.02,
        "metallicFactor": 0.6,
        "clearCoatMap": "/vehicles/coupe/coupe_main_cc.data.png",
        "normalMap": "vehicles/coupe/coupe_main_n.normal.png",
        "opacityMap": "/vehicles/coupe/coupe_main_c.data.png",
        "baseColorMap": "vehicles/coupe/SKINNAME/coupe_skin_SKINNAME.dds",
      },
      {},
      {}
    ],
    "activeLayers": 2,
    "dynamicCubemap": true,
    "materialTag0": "beamng",
    "materialTag1": "vehicle",
    "order_simset": 0,
    "version": 1.5
  },
}