Texture to carshape or carshape it doesn't matter which.
If you make the carshape first from scratch you can customise where the parts of the skin are located by uvw mapping them to the part of the texture you want. Using 3ds max for example. And exporting the wireframe to a template and then painting the car from there.
If you already have a texture and want to make the carshape you can do the same thing in reverse.
Either way you need a program like 3ds max and knowledge in uvw mapping. It's very hard at first but if you want to search for some "uvw mapping" tuturials.
I'm pretty sure zmodeler can do it, but it's a bit limited. Others here might be able to help you a bit more.
Oh the other way.. the easier way would be just to use an image program like photoshop to edit and copy the parts from the minardi texture like the front wing for example.. and then pasting them onto the midland texture.. making sure they were the exact same size and shape. And the sponsors are in the same locations. In some cases you would need to stretch the parts in hieght or width. But that would take some good photoshop skill.
There is no easy way to do it.