@501.legion go into the server folder \cache\http-files and delete assets.rpf and the assets.sfi (assuming you named the folder for vehicle mod assets; otherwise delete the .rpf and .sfi that corresponds with the folder name)
I am assuming you went back into resources and deleted the assets folder
make sure you edit your citmp-server and remove the line you input for the car mods.
If you need help setting up the server files I will just go ahead and upload a .rar of my server folder. I have no issues with mine.