Combining Non-ELS vehicles into one resource

I’m a DEV on a server that uses a mix of ELS/NON-ELS vehicles, ELS vehicles are easy enough thanks to some software but with non els vehicles, I can do the vehicle.meta/caravations/handling files fine in the software but can’t do the carcols, could some be able to help m,e or point me in the direction of a good tutorial, please?

What do you want exactly?