Add-on Vehicle appears Matte no matter what I change

HI all.

I've recently downloaded an add-on vehicle, complete of all necessary meta files and the rest.

There is only one problem, the texture appears matte or satin and I've found no fix for it by screwing around in the carvariations color section and neither Native Trainer works.

The vehicle is always spawned with a livery and there's only one.

Does anyone know how I could change it to spawn with a classic (reflective) livery or where I should be looking?

The vehicles works fine in everything, it's just that it looks matte while it should look reflective.

This must've been a mistake from the creator, but I would like to fix it myself if I can.

I'll leave a piece of code, I replaced references to the vehicle as I'd like to keep it private.

carvariations.meta

<CVehicleModelInfoVariation>
  <variationData>
   <Item>
      <modelName>CUSTOMCAR</modelName>
      <colors>
        <Item>
          <indices content="char_array">
            4
            12
            0
            0
            0
          </indices>
          <liveries>
            <Item value="true" />
          </liveries>
        </Item>
      </colors>

content.xml

   <Item>
      <filename>dlc_CUSTOMCAR:/common/carvariations.meta</filename>
      <fileType>VEHICLE_VARIATION_FILE</fileType>
      <overlay value="false" />
      <disabled value="true" />
      <persistent value="false" />
   </Item>

As I said, I've tried changing color codes to no success and even changing the content.xml overlay to true, disabled to false and persistent to true (just to give it a shot) had no difference.

Thanks