How to create a skin template with Content Manger when the car didn´t come with one.

You can use Content Manager for this:
Open the Content Tab of the car and click on CM Showroom.

1. Click on the main body part of the car.
2. Click on the three dots besides the "txDiffuse".
3. Click on Calculate AO and choose "Calculate map of custom size". Type in "4096x4096". It takes some time to render. Click on the image and then you can safe it via the disc icon in the lower left corner.
4. You can also export the wireframe by clicking on "view mapping"

Import the files into different layers of your graphics programm, start painting and follow the guide here:
https://thracing.de/community/custom-skins/make-and-use-a-custom-skin-in-thr-races/#post-17