Put the new decals just below the layer called DECALS.

Make sure you have the latest DXTBMP to convert textures. Older version will export as 2048. These textures need to be 4096.
Choose DXT 1 no alpha to keep the file size low since there is no alpha channel.


Based on version....
For the 64 bit models that have PBR (P3D V4.4 or higher) Use the chrome channel on top. 

For the 32 bit models that DO NOT have PBR (P3D V4.3 or lower or FSX) turn OFF the chrome channel on top. 