So, today i was talking with some GTA SA singleplayer modders, i asked them if they could add new cars without replacing stuff from the base game, they've said "Yeas". They copie pasted this mod to me http://gtaforums.com/topic/733982-fastman92-limit-adjuster/ --- Its about expanding the pre-existing id limit to add more maps, weapons, cars and peds. If this had been integrated with MTA it could improve even more the mod. With this "id limit expansion" we could see thousands of new weapons and cars, peds and more maps to land on.