I do not have intention to edit kunos orginal cars at all, but im just curious. if some one edit kunos original vanilla content cars for their personal use, is it a fair use? or a copyright infringment?
I think it's the uploading/distributing of copyrighted files that break the agreement, so doing whatever you want with them for personal use is fine. Could be wrong.
I'm also pretty sure you can't play the game on an oil rig without permission from Kunos though. Just in case you were wondering.