I think you're importing 2005 Nextel cup paint schemes into the MENCES19 MOD
as part of a Carset
That's impossible to do and make it work like he's doing. Because even if you export a TGA from one mod and import it onto a carfile in another, unless the templates and models are the same it won't line up right. It'd have to be something like exporting a MENCup17 Fusion onto a MENCup18 Fusion.
Since the 2005 cars look nothing like the MENCup19 cars there's no way they'd line up right. Even if he was importing, to get them to look like they do in the renders would require a lot of editing and tweaking of the original TGA. With all that work it makes more sense just to paint them from scratch, which is what he's doing.