static IniTaxiJob(vehicleid)
{
    switch(GetVehicleModel(vehicleid))
    {
        case 420,438: return 1;
    }
    return 0;
}

public OnPlayerEnterVehicle(playerid, vehicleid, ispassenger)
{
    if(!ispassenger && IniTaxiJob(vehicleid)) return RemovePlayerFromVehicle(playerid)l
    return 1;
}