You are not allowed to convert and/or release a car without permission.
Ask the original author for permission to be allowed to modify a car, which you have not modelled by yourself,
if you want to convert it for a game.
You have to note the original author in the readme file, bundled with the realease,
if the original author gave permission to edit the car (that contains tuning, conversion and hosting on other websites).
If the car is from another game, the game name has to be noted in the readme file and the thread, too.
Additionally to that all corresponding persons must be named in the readme.
If you can't find a clear answer, where the car comes from or whether it's allowed to convert it, note that in the readme.
Also you should write, that in copyright issues all links and images will be removed.
In general you are only allowed to post screenshots and download links if you have all permissions for the addon!
Creating new threads for modding should follow these rules:
[W.I.P.]... => Work In Progress
[CON.]... => Conversion
[REL.]... => Release
[UPD.]... => Update
The owner of this website is not responsible for any conversion discussed in this forum!
~Edit~ ~[UPD.] added~ ~A_M~