I'm in the beginning of making this car so this is the first time i imported it. i made the car with blender and imported it into the game and this happens. I made it with the mirror tool in blender and it seem's that the game only takes the other side of the car. This is my first time trying to make a mod so it might be something really stupid.
In the exporter in Blender (if you're exporting to .dae or .obj or whatnot) there should be a check box for applying modifiers, which needs to be on to mirror properly. If that option isn't available in the exporter, simply apply the modifier, export, then undo to get back to your mirrored mesh.