Many new vehicles have been made, but the game has a limit of 12. As I couldn't find a way around it via editing normal files, I guess it's coded. If so, could OJP give a shot at removing the limit?
Sure, but we'll need the SDK first thou.
They probably have it capped off at 12 for a reason like it lags the game out too much like when you spawn 20 bots.
The limit is the amount of vehicles you can have in your base folder. You can spawn endlessly in the game self, I believe.