Nitpick: unless I just popped into an alternate timeline, Kauai is American [1].
A lot of the "don't do this" rules on a rental are just so they can stick your insurance with the cost if you break it.
In reality, if the damage is very slight and the person checking them in doesn't want to do the paperwork, it's going to slide.
If you do drive off-road in a rental, wash it before returning it.
And while they do run out, most of the time you will receive what you booked, and at larger airport locations they'll typically substitute something close in size and nature to what you booked if they do run out of your specific class.
Not so long ago Ireserved a car, from a large national company, to go on a backpacking trip. I picked an early pickup window, so I would have time to drive a substantial distance, hike, and get to my desired stopping point before nightfall. I arrive at the rental place at 8a, and find that they're fully staffed but had only a a single large van available for rent. If I waited around until mid afternoon, I was told, _maybe_ something would show up. One of the staff told me that the prior week corporate had decided to open up that site even though there were no cars.
I'm surprised that Turo/Getaround/etc don't message more aggressively about "you'll actually get the car you want, when you want, which somehow most car rental companies think is unachievable."
See:
https://www.hertz.com/rentacar/vehicleguide/index.jsp?target...
Which is why it's almost best to just rent the lowest, cheapest thing, because they'll give you whatever they have.
This stops working when you need a particular aspect of whatever it is, especially if it's an aspect nobody really "cares" about - like whether it is EV.
Most people care it has enough seats, and enough luggage room. So a larger SUV works as well as a car for them.