#Bigg Boss93 :
You can fix it increasing the base(paintable) texture size, go in your *\cars\textures\ folder and resize every color texture to 1280x1280, that way you'll have way less jaggies.
WARNING! the game doesnt like textures bigger than 1280x1280, so once you go over that it will start acting weird, removing textures from the objects and parts and crashing more often.
now I have the resized png pictures. When I want to make them to .1 files, .2, etc... My system still says that they are pngs. What do I do then?