new bool:COD;
new VehiculosGuerra[MAX_PLAYERS];

if(COD == true)
{
     VehiculosGuerra[playerid] = CreateVehicle(425,...);
     VehiculosGuerra[playerid] = CreateVehicle(432,...);
     VehiculosGuerra[playerid] = CreateVehicle(520,...);
}
else if(COD == false)
{
     for(new i = 0; i < MAX_PLAYERS; i++)
    {
          DestroyVehicle(VehiculosGuerra[i]);
    }
    return 1;
}

new VehiculosGuerra[MAX_PLAYERS];
----------------

CMD:AUTOSCOD...........bla bla bla.........
----------------

CMD:CODOFF(playerid,params[])
{

for(new i = 0; i < MAX_PLAYERS; i++)
    {
    DestroyVehicle(VehiculosGuerra[i]);
    }
return 1;
}
------------------

case DIALOGO_COD:
  	{
		    if(response)
		    {
		        switch(listitem)
		        {
		            case 0:
				 {
                     DestroyVehicle(VehiculosGuerra[playerid]);
                     new Float:X,Float:Y,Float:Z,Float:ROT;
                     GetPlayerPos(playerid,X,Y,Z);
                     GetPlayerFacingAngle (playerid,ROT);
                     VehiculosGuerra[playerid] = CreateVehicle(432,-9017.8018,-2270.8801,761.9372,ROT,-1,-1,60); SetVehiclePos(VehiculosGuerra[playerid],X,Y,Z);
                     PutPlayerInVehicle(playerid,VehiculosGuerra[playerid],0);
					}
					case 1:
					{
                      DestroyVehicle(VehiculosGuerra[playerid]);
                      new Float:X,Float:Y,Float:Z,Float:ROT;
                      GetPlayerPos(playerid,X,Y,Z);
                      GetPlayerFacingAngle (playerid,ROT);
                      VehiculosGuerra[playerid] = CreateVehicle(520,-9017.8018,-2270.8801,761.9372,ROT,-1,-1,60); SetVehiclePos(VehiculosGuerra[playerid],X,Y,Z);
                      PutPlayerInVehicle(playerid,VehiculosGuerra[playerid],0);
					}
					case 2:
					{
                     DestroyVehicle(VehiculosGuerra[playerid]);
                     new Float:X,Float:Y,Float:Z,Float:ROT;
                     GetPlayerPos(playerid,X,Y,Z);
                     GetPlayerFacingAngle (playerid,ROT);
                     VehiculosGuerra[playerid] = CreateVehicle(425,-9017.8018,-2270.8801,761.9372,ROT,-1,-1,60); SetVehiclePos(VehiculosGuerra[playerid],X,Y,Z);
                     PutPlayerInVehicle(playerid,VehiculosGuerra[playerid],0);
					}

		        }
		    }
		}

new bool:_@CODIsActive;

public OnFilterScriptInit()
{
    _@CODIsActive = false;
    for(new i = 1, j = GetVehiclePoolSize(); i <= j; i++)
    {
        if(GetVehicleModel(i) == 425 || GetVehicleModel(i) == 432 || GetVehicleModel(i) == 520)
        {
            DestroyVehicle(i);
        }
    }
    return 1;
}

CMD:cod(playerid,params[])
{
    _@CODIsActive = true;
    return 1;
}

CMD:codoff(playerid,params[])
{
    _@CODIsActive = false;
    for(new i = 1, j = GetVehiclePoolSize(); i <= j; i++)
    {
        if(GetVehicleModel(i) == 425 || GetVehicleModel(i) == 432 || GetVehicleModel(i) == 520)
        {
            DestroyVehicle(i);
        }
    }
    return 1;
}

Defines la variable de los vehiculos de guerra:
new AutosG[MAX_PLAYERS];

En cada auto, bueno yo lo tengo asi:
CMD:rhino(playerid, params[])
{
	if(AutosG[playerid] != -1) DestroyVehicle(AutosG[playerid]);
	new Float:x, Float:y, Float:z, Float:angle;
	{
		GetPlayerPos( playerid, x, y, z );
		GetPlayerFacingAngle( playerid, angle );
	}
	AutosG[playerid] = CreateVehicle(432, x+3, y, z, angle, -1, -1, 300);
	LinkVehicleToInterior( AutosG[playerid], GetPlayerInterior( playerid ) );
	SetVehicleVirtualWorld( AutosG[playerid], GetPlayerVirtualWorld( playerid ) );
	PutPlayerInVehicle( playerid, AutosG[playerid], 0 );
	GameTextForPlayer(playerid, "~g~~h~rhino", 6000, 5); //-Rhino
	SetVehicleHealth(GetPlayerVehicleID(playerid), 1000);
	PlayerPlaySound(playerid, 1133, 0.0, 0.0, 0.0);
	return 1;
}

Si hay un rhino, hunter o hydra en el mapa y la guerra estб desactivada:
public OnPlayerStateChange(playerid, newstate, oldstate)
{
	if(Informacion[playerid][Evento] == 0) // tu variable de evento
	{
		if(newstate == PLAYER_STATE_DRIVER)
		{
			if(AutosGu(GetPlayerVehicleID(playerid)))
			{
 				RemovePlayerFromVehicle(playerid);
				GameTextForPlayer(playerid, "~w~El evento ~g~~h~guerra total ~w~esta desactivado~n~no puedes usar este vehiculo!",6000,3);
			}
		}
	}
	return 1;
}

Stock para ver en que auto entra:
stock AutosGu(modelo)
{
	switch(GetVehicleModel(modelo))
	{
		case 432,520,579: // ID DEL RHINO, HUNTER Y HYDRA
		return 1;
	}
	return 0;
}
Y en tu comando para desactivar la guerra, destruirб todos los vehнculos que tengan un vehiculo creado por el comando:

for(new i=0;i<MAX_PLAYERS;i++)
{
	GameTextForPlayer(i, "~w~guerra total ~g~~h~~h~desactivada!", 4000, 3);
	PlayerPlaySound(i,1057,0.0,0.0,0.0);
        Informacion[i][Evento] = 0; // usa tu variable
	DestroyVehicle(AutosG[i]); //destruye todos los autos de la guerra
}