It's not a gimmick if the FPO is included in the price then you can return the car empty; shouting at you that you are low on fuel; bleeping that you are low on fuel; having the mileage remaining flashing ----- at you, whilst you hope that the car will make it up the ramp to the Hertz dropoff

As the Hertz link doesn't change the country to where the specific offer is, I'll guess that this is a Japan / Asia promo ?