MKE has the worst selection I've ever seen with National. It's usually pretty cheap, which may be connected.

The regular aisle is usually Vibes. Occasionally a G6, but more often than not just Vibes. Used to be HHRs. Presumably they figured if you've only stocking one model it's best to have something versatile.

The executive selection is generally a choice between an Impala or a low-option Altima. Sometimes a Grand Prix.

Some weekend times and late at night they just close the aisle and you have to go to the counter.

In maybe 20 rentals over more than two years I have never, ever, seen anything other than the above models on either aisle. Not even a Buick.

Did get a Malibu once, right when the new model came out, but that was when the aisle was closed. Another time it was closed they offered a Pacifica or Acadia.