I am currently preparing a mod for my GP2 team in order to explore Rfactor posibilities for driver´s training. When building the .pm file I have realised that the origin for the coordinates in this file are not very well explained.. I mean that the official ISI modding guide tells that the (0,0,0) point is located on ½ of the wheelbase at chassis bottom tub height. However, after analysis of several mods previously done for GP2 I have seen that in those cases, the (0,0,0) point is not located at ½ wheelbase. In fact an example of Z coordinate (in Rfactor axis system, not in a SAE-type one) for the front spindles is -1,65m and 1,35m for the rear ones. So the (0,0,0) point clearly is not placed at mid wheelbase! Where should I place the origin (0,0,0) for coordinates in the .pm file in order to build a good car model? Or does this have no influence at all? On the other hand I would like to know also what is the meaning for the values in brakets in the following mod´s .pm file: [JOINT&HINGE] posbody=rl_wheel negbody=rl_spindle pos=rl_wheel axis=(-1.0,0.0,0.0) Are they the (X,Y,Z) coordinates of this corner joint?