The car itself
They have not fixed over charges they charged due to mileage overages on an unlimited mileage rental. They haven't responded to fix it. The pick up of the car was ridiculous, bad communication, giving me a car I didn't rent initially. I rented a mid-size SUV and they tried to give me a compact car, saying it was an SUV. Took over an hour just to pick car up as rental agent appeared to be incompetent. In the end, they overcharged for for a day and mileage - and have since failed to respond to my multiple attempts to resolve the incorrect charges.