I have tried everything i can, i have watched tutorials, it just doesn't work, does anyone know what i am doing wrong. I have put the DDS files to the dds folder, and put the XR.VOB folder to the Veh folder, but it doesn't work, that was the only thing shown in the tutorial, the only thing that my mod folder doesn't have is TWEAK.

The only official way to add mods is to use the official Vehicle Mods system integrated into the game. You can create mods using LFS Editor or choose from more than 2800 mods by clicking the "Mods" button in garage.

There is a guide for mods in LFS Manual: https://en.lfsmanual.net/wiki/Vehicle_Mods