You should create a default Decal UV layout, to which you try to conform all cars and all decals, that way you don't need to create a new unwrap for every decal, which sounds like a bad idea (too much work, impossible due to max 4 UV's).
What I have is a car skeletal mesh and I want to add decals on it like flames, stripes, etc. Now I want these decals to be used among several different cars and recreating them for each vehicle would take up a large amount of harddisk. So what I want to do is create a new uv layout for every decal like you can do in max.…
Alright. So how I plan to do this now is. The first UV is going to be the normal map which is symmetrical. The second UV is for the diffuse, for cars that have custom paint jobs* (sponsor stickers, logos, etc) The third UV is for decals. Such as flames on the side of the car, or strips. These will be located on a 2048^2…