I recently downloaded a police mega pack which added extra police vehicles into the game that i was able to spawn using my trainer. I think it went up to Police9. I was able to spawn them no problem, but when i tried to add some more vehicles on top of it, in game it would say invalid model including the ones i'd previously been able to use. Is there a way to use those regular models as addons? Just some insight would be helpful. I know it can get pretty tricky.