Surprisingly, Mustang is quite lucrative because more than 50% of domestic sales are higher series V8s
and international sales are just dominated by V8s save for maybe China and it's import capacity taxes.
On two of my trips to SoCal, I rented a Corolla and a Sentra. The Sentra was less of a shitbox than the Corolla. I'm not sure why the Corolla is still available and the Focus and Cruze aren't. But maybe that's my domestic bias showing. (the other time in SoCal was a family trip, we rode in my dad's E150 conversion van)