How would one use Adobe substance painter for vehicule custom?

Hi !
im trying to get into gta 5 vehicle custom , and i see a lot of people are doing liveries and customisation, with photoshop, like painting in a 2D space , but I would like to use adobe substance painter ,since it's specially made for texturing, it would permit much more possibilities , it seem easier in a 3D space .

the thing is I want to custom base vehicle, which I extract from either OpenIV or Codewalker , so I usually end up with YFT files which I'm able to import in 3dsmax ,
the thing is , I need a proper model (like .obj or .fbx) with clean UV's to import it in Substance painter , and , the vehicles I get when I import em in my software have these kind of UV (attachment) , which substance painter absolutely hate !
Im not sure if I have the wrong workflow, but all vehicle seems to have these kind of uv's and I don't even know how the car body textures maps would look like



the thing is , I know 3D but I dont know much about modding , and gta files, but I guess organising the uv of the model will not work because : I cant export a texture map with "cleaned" uv and give it to someone who has a base model with the base uv , can i ? because my textures would be made for the clean uv's not for the base game uv's ?

It's kind of a brain game that I can't resolve.

the big question is, how the hell can I achieve a workflow that would be something like : exporting base vehicle model from game -> converting it to a usable mesh (obj/ fbx) -> importing it in adobe substance painter -> texturing it with cool pattern and all -> exporting textures -> giving the textures to a dev friend who would like to add em in, for example, his server's garage .

thanks ,and sorry for the possibly bad english