Not that it directly applies to this, especially because you didn't actually specify what you're trying to do, but as an aside, if you're matching over from Hertz to National, I would just mention that I've recently found that Hertz's elite statuses have been essentially worthless. I've been Hertz PC for over a year now, and I've found their service to be steadily decreasing. First they downgraded PC from a 2-class upgrade to a 1-class, then they made it only if available. As a PC I haven't been getting any special treatment or cars any nicer than I would have otherwise gotten. (Interestingly enough, I found this to be especially true in NYC airport locations, you can read into that what you like.) I finally got sick of it to the point where I matched myself to National Exec Elite and have been using them of late, and I gotta say, the service has been superb thus far. In my last two rentals, one I landed in EWR and the entire Emeral Exec Aisle was Maximas, Avalons and Yukons, I drove a brand new well-appointed Avalon with 6 miles on it, the second rental was in MIA, the Emerald Exec Aisle was mostly empty, so with very little pushing, I got the attendant to give me a free upgrade into the Camaro Convertible that they had parked there for the upsell. In both cases I only made for a midsize!
So to those trying to match in the other direction, I would be wary.