Mine is a little different though mine just says vehicles but not sure if that would make a difference.
Is there another way to add cars or to fix this? I was trying to add this thing called Spark IV so I clicked add to and then tried to find the vehicles.img but it was corrupted. When I click on it it says this file is corrupted so I don't know what to do. So I was watching this video and I was trying to add car mods which I think is when I just add a car that I want to the game and I got to the part of the video at 7:27 where he goes into vehicles.img.