[Diogo123]

pawn Код:

if(strcmp(cmd, "/sirene", true) == 0)
{
new objectid = CreateObject(19419, 0, 0, 0, 0, 0, 0);
AttachObjectToVehicle(objectid, GetPlayerVehicleID(playerid), 0.009999, -0.019999, 0.944999, 0.000000, 0.000000, 0.000000);
SendClientMessage(playerid, COLOR_YELLOW, "sirene adicionada");
}
else
{
RemoveAttachObjectToVehicle(objectid, GetPlayerVehicleID(playerid), 0.009999, -0.019999, 0.944999, 0.000000, 0.000000, 0.000000);
SendClientMessage(playerid, COLOR_YELLOW, "sirene retirada");
return 1;
}

adapta para o seu gosto