Send email to admin before Rent end. For that you need create CRON job and connect to Cron check so URL: http://{yours site}/index.php?option=com_vehiclemanager&Itemid={Yours ItemID}&task=rent_before_end_notify with span - every day. Cron Jobs may look like:"wget -q -O - http://localhost/index.php?option=com_vehiclemanager&Iteid=56&task=rent_before_end_notify /dev/null"