IIRC, the reservation needs to be on an AAA rate for other AAA members to be free additional drivers. This should work at the exit booth, but many exit guards are contracted out so good luck.

It is an AAA rate, so should be good on that front. Guess we might have to go to the desk /:

Adding additional driver a few hours later
 

My father is flying into couple of hours before me, have a reservation under his name (He has PC), was wondering if it's possible for him to pick up the car and then come back in a few hours and add me as an additional driver once our rental agreement has began?

Yes. You can go to the counter once you arrive. He has to be present too.

You can add an additional driver at any location after the rental has started. Doesn't have to be the renting location.

A few years ago, I was helping a friend drive a Penske rented truck from Alabama to Illinois. After he booked the reservation he gave me the confirmation number. I brought this number to my local Penske office along with my driver's license; they were able to add me as a second driver to his reservation long before I flew to Alabama to help him out. I would bet that this would work with Hertz as well - that way you won't have to stop at any rental counter after you land.

This won't work. Rental car companies are very strict. I'm guessing that was a Penske contractor/franchisee which let you do it.

Additional Driver in the middle of trip?
 

My second driver won't be joining me until the second half of my trip. Can we stop at any Hertz location to add the second driver? Also will they back charge for the entire trip on the second driver or just the days left on the reservation?

Hertz says that a driver can be added at any time during a rental:

https://www.hertz.com/rentacar/produ...=globNav_3_5_1

You'd have to inquire about charges.

If you are Pres Circle then you usually bypass the counter. I assume you need to call the Hertz Reservation # to add the non-spouse additional driver? Or do you do it at the rental location counter?
I tried at an HLE in Indio (CA) and was told the contracts are pre-printed prior to rental time and changes have to be made by reservations- when I called reservations was told cannot change a contract
after it has been issued.

Was I just screwed around or is there a proper procedure?

You were just given wrong info, either because of incompetence or laziness. There is actually no way on the Hertz website (or via the reservations line) to name an additional driver. That has to be done at the counter at HLE locations, or it can be done at the exit booth at Ultimate Choice airport locations.

Adding a 2nd driver online?
 

Can I add a second driver online while making reservation - I am likely choosing "Pay it now" option?
Its one family with same last name - are you required to add the additional drivers?

A second driver would need to be added at the counter or at the exit booth. You cannot add an additional driver online. It doesn't matter where it's a pay now or pay later reservation. Either way, the additional driver needs to show their driver's license at the location.