The first post in that thread contains the info, some of which is in a link to the T&Cs. Look under the current gift card offers - the Hertz is one a several. In short, there's no promo code to enter for the Hertz offer, and it should automatically stack with any other offer as long as you meet its terms.

I cannot combine the info, as I'm not a mod, but we do *not* want the mod to combine threads because that mistake was made in the past and the sticky was ruined. That thread is more comprehensive than this one, but not as old, and the OP being first is vital. This one really should be locked and pointed to the sticky *without* being merged.