I changed the wording to help people understand that we simply set aside 2 days of rental costs then come back and extend for 2 more days. We did this instead of renewing every day because it would be to costly for us to do the extend transaction for 400k cards every single day. So we cut it in half by doing 2 days.
As you may or may not know rentals are only promised for a 24hr period so during the second day if it is no longer available we will begin looking for another card for you.
Auto Rentals means it auto attempts to rent that monster at that level for forever until you cancel or pause. We just keep extending as long as the conditions are appropriate.