you need to open the .gp4 fiels with a hex editor and change aot of the stuff from "bar" (or jordan) to "arrows".
Failing that, you need to do it in Z-Modeler, which might be easier if they use different texture names from the normal textures. Its not as easy as you might think in otherwards :'
Racing Is Life. Anything that happens before or after is just waitingJesus may be able to heal the sick and bring the dead back to life, but he can't do shît for low fps