[Doughty]

Hello Akcent, try that:

pawn Код:

if(!strcmp(cmd, "/respawnallcars", true) || !strcmp(cmd, "/rac", true)) //
{
    if(PlayerInfo[playerid][pAdmin] < 1337) return SendClientMessage(playerid, COLOR_GRAD1, "   you are not authorized to use that command!");
    new bool:unwanted[CAR_AMOUNT];
    for(new player=0; player<MAX_PLAYERS; player++)
    {
        if(IsPlayerInAnyVehicle(player)) unwanted[GetPlayerVehicleID(player)]=true;
    }
    for(new car = 1; car < 400; car++)
    {
        if(!unwanted[car] && !IsATLCar(car) && !IsATrailer(car)) SetVehicleToRespawn(car);
    }
    GetPlayerName(playerid, sendername, sizeof(sendername));
    format(string, sizeof(string), " Toate vehicule sau respawnat de %s.", sendername);
    BroadCast(COLOR_WHITE,string);
    return true;
}

Edit: You can do the code that the user above wrote.