I am making a car mod (new Yugo mod) and I made a plenty of upgrades, like different engines, transmission, bumpers, stuff like that.. Because I wanted to make different classes, as in real life racing. I also categorized upgrades under "class upgrades" according to the real classes rules. Let's say similar to the ones on original ISI's Rhez.. But I never thought of how would the classes system work in online play.. And I am not sure if in multiplayer it is possible to fix upgrades to only one class and play with it.. I also couldn't find any way of allowing only one kind of upgrade under dedicated server settings.. I found some "upgrade checker" tool, but I don't understand how it functions, it mentions .xml files which I never came across in rfactor. So.. How are upgrades actually handled?? And also, taking all this into account, it seems to me that fixing classes and upgrades is pretty complicated for server admins.. Do you think it is better then that I make separate cars for each class instead of "upgrade class" system?