I do not own a Tesla, but I have ridden in one without knowing this. This is not the fault of the passengers. This feature should be obvious to anybody in the vehicle, not something you have to rtfm for.
The charging people for mileage on unlimited mileage rentals scam isn't working
The charging people for gasoline on EV rentals scam isn't working, better sell the cars.
All you hear about Hertz is how they're trying new ways to gouge customers that are such obvious bullshit that it makes people paying attention swear them off. I would never rent a car from them.