[iFiras]

pawn Код:

public OnPlayerCommandText(playerid, cmdtext[])
{
    if(strcmp(cmdtext, "/tunecar", true) == 0)
    {
        if(IsPlayerVipType(playerid,2))
        new playerstate = GetPlayerState(playerid);
        if(playerstate == PLAYER_STATE_DRIVER)
        {
            return ModCar(playerid);
        }
        else
        {
            return SendClientMessage(playerid, COLOR_RED, "[ERROR]: You must be in a car being the driver Or You Not Gold VIP");
        }
    }
    return 1;
}

You shouldn't be using "if" as "If", case sensitivity is required.
In addition, you shouldn't use a semicolon in "if" statements.