I finally managed to get a decent rate for a reservation with Hertz (via an agent), from SFO for a "full-size" car.
I wanted to inquire directly with hertz about upgrades. Given that it's a long term rental I am worried about availability. Shall I inquire now or on the day?
I don't mind if I don't get the upgrade, but i'd be willing to pay extra for a higher class, due to the long rental period...