[Diogo123]

tenta esse

if (strcmp(cmdtext, "/trancar", true) == 0)
{
if(GetPlayerState(playerid) != PLAYER_STATE_DRIVER) return SendClientMessage(playerid,COLOR_RED,"Apenas o motorista pode trancar o carro!");
new vehicleid = GetPlayerVehicleID(playerid);
for( new i=0;i<=MAX_PLAYERS;i++) {
if(i != playerid) {
SetVehicleParamsForPlayer(vehicleid,i, 0, 1);
GameTextForPlayer(playerid,"~w~ Veiculo ~r~Trancado!",1000,1);
SendClientMessage(playerid, COLOR_WHITE, "Carro trancado!");
}
}
return 1;
}