French efficiency is indeed low, the most unreliable thing was that the car indicated low oil level in less than a day. We were two girls, confused and called their customer service, using up all our phone credit, and still no resolution. They even asked us to call the Belgian hotline, which was ridiculous. Ultimately, we found a solution through Baidu and a friend's guidance to check the oil dipstick. Fortunately, there was a garage nearby, where we found out there was almost no oil left, any further driving could have damaged the engine. We spent our own money to add oil and coolant, and after that, everything went smoothly. The car had only driven a little over 10,000 kilometers, quite new for a rental car, and yet this problem occurred. When we returned the car, we informed the staff and they said they would deduct the repair costs from the fee. The final bill showed a reduction, but it was charged in dollars with Dynamic Currency Conversion, causing some exchange rate loss. I generally like HERTZ, and despite experiencing the unreliability of the French service, everything went relatively smoothly otherwise.