Another tier match is via my Noir MGM status.
Got me Ambassador Elite at Marriott Bonvoy, which in turn got me President's Circle at Hertz (I was already Gold Circle via Platinum AMEX) - Once you reach this level, you'll enjoy a free additional driver, the widest selection of vehicles available, guaranteed upgrades and a dedicated customer service line.
Not sure what Ambassador Elite is good for, but with President's Circle I may rent a less expensive basic car I believe, and then just pick up about anything in the President's Circle area.
Or at least that is the way it works with Caesar's Seven Stars match that got me Executive Elite at National Car Rental.
However, I typically just use HotWire to find the least expensive rental anyway which is strange that even the least expensive car at National or Hertz (which I may use free to upgrade to any vehicle) still winds up more expensive than just paying straight up for a mid sized SUV at HotWire.