I can't get any cars loaded anymore in the tuning section of rF2. Normally it wasn't any problem, didn't change anything (I think). I'm trying to paint a few cars for the next season of racing, and then it comes in handy that I can check my workprogress ingame.
Sometimes it seems to take a very long time for a car to load but as you're not new to rF2 I'msure you're aware of this. Maybe select a different default skin of the car and do the create directory for it or use the mas package method. Do a steam file integrity check for the game. Maybe even uninstall and delete the mod and any associated listings using the launcher, restart pc and reinstall the mod. Last resort, fresh rF2 install. Good luck and let us know how you go.