There are plenty of people that know how to do it I'm sure. I feel like its not that hard even.
The way I do it, is make sure you have something to open the TXD with and save the textures with. Then get Zmod 1 and 2. First open the TXD and save all the textures, then open the DFF with Zmod 2, and save it as an old z3d file. Then open that file with Zmod 1. Rename the material names. Then export the body as a DOF, then the wheels separately as a DOF (note, most GTASA models come with a single wheel so you have to rotate it to get a left and right side wheel).
Also once imported into Racer, and the shader has been taken care of you'll more than likely find the model to be too big, I use Racer's modeler to scale it down, usually it doesn't need to be scaled down much though (95% comes to mind for me)[/