[NeroX98]

I'm not proffesional scripter but if i was you, i would make like this:

pawn Код:

//Put this on top of your gamemode
forward MessageTimer(playerid);
new AlreadyShowed[MAX_PLAYERS];

//Under OnPlayerEnterVehicle
public OnPlayerEnterVehicle(playerid, vehicleid, ispassenger)
{
    if(AlreadyShowed[playerid] == 0)
    {
        AlreadyShowed[playerid] = 1;
        SendClientMessage(playerid,COLOR_RED2,"YOUR MESSAGE HERE");
        SetTimerEx("MessageTimer", 5000, false, "i", playerid); // change 5000 if you want :)
    }
    //rest of your code
}

//Somewhere in your gamemode
public MessageTimer(playerid)
{
    AlreadyShowed[playerid] = 0;
    return 1;
}