Combat Arms isn't even Nexon's game, or is it? If it isn't they won't be able to add any "new" stuff like vehicles, i think they'll have to update the game according to the real owner and creator of the game.
If it is nexon's game, all the coding and modifying will take a hell lot of work, not to mention all the people that's needed to do the modifying and testing (also upgrading/changing hack-preventing systems), especially not to mention spending a hell lot of time and work (even money to hire the work force) doing all that for a free game.
If it is nexon's game, all the coding and modifying will take a hell lot of work, not to mention all the people that's needed to do the modifying and testing (also upgrading/changing hack-preventing systems), especially not to mention spending a hell lot of time and work (even money to hire the work force) doing all that for a free game.