WTFsandwich

I downloaded a few of hte car mods off of here and I replaced the .txd and .dff just fine but when I go to edit handling.cfg and vehicle.ide I don't know if I'm doing it right. I screwed up the install last time I tried. Could it be the version I have? I don't know which one I have. Could someone point me in the right direction of how to make the car mod work?