Avis - Additional driver mid-rental (And domestic partner) question

I have an upcoming week-long rental and just need someone (non-coworker, non-domestic partner) to drive the car the last 2 days of the reservation.

Has anyone been able to add a driver mid-rental? If I split the rental up onto 2 reservations (1 for me, 1 for them/both of us), it would add about $150. I'm wondering if Avis will let us add a driver for the last 2 days without splitting the ressie. Doubtful, and I've sent Avis a note asking, but thought I'd get a faster response here knowing how well Avis responds.

And another question (that I'm waiting on an Avis response), does anyone know the current Avis definition of "Domestic Partner (http://www.avis.com/search/SearchMain.jsp?question_box=additional+driver&question=lew&ui_mode=question&charset=UTF-8&language=en-US&site=Avis&searchtype=WebSearch&user.segment=avisnew)" that allows the 2nd driver to be free? I know a few years ago, Avis said you must have the same address listed on your license. My issues with them using this as a valid determination:

Anyone in your family could be considered a "domestic partner" (kids/live-in nanny/live-in house keeper/etc)
It's not too difficult to get a license at an address where you frequent but don't necessarily live
Many people move and both spouses don't always update licenses immediately
Many people have multiple residences and both are necessarily licensed at the same residence (tax purposes..)



Not that I know a better way to make a DP determination, but just playing devil's advocate :D

I believe you can add drivers at any time by going back to the rental location, and maybe even any avis location. Not sure about domestic partners, but I suspect if you look the part, they won't question it. Just a hunch, though. I know Costco waives the additional driver fee with their awd. Even without using it, I have had mixed results getting it waived by simply mentioning it to them when picking the car up.

If you join the British Airways FF program (Free to join) then you can have a free additional driver using their AWD. I am not familiar with AVIS but some other companies calculate the additional driver fees for the whole duration of the rental period even if you only require the last few days

If you join the British Airways FF program (Free to join) then you can have a free additional driver using their AWD.

So it's not enough to just show the BA card when collecting the car? The BA AWD gives me a worse rate than the AWD from work, so I was planning to just flash the card when I got to the rental desk...

So it's not enough to just show the BA card when collecting the car? The BA AWD gives me a worse rate than the AWD from work, so I was planning to just flash the card when I got to the rental desk...

Nope :( The Costco rate also gives a second free driver at "select locations." I've used this a few times and it always worked.