The car rental company explained things quite clearly before picking up the car. They held a 10,000 Thai Baht pre-authorization and mentioned that it would be refunded within two weeks if no issues arose. Note that MFlow cannot be used, and the policy is full-to-full for fuel. There is a gas station near the airport. Driving in Bangkok city can be challenging due to heavy traffic, but roads in the provinces are much better. I booked a Honda City but received a Nissan Almera instead, which seems to be the Southeast Asian version of the Sunny. The trunk is spacious enough to fit three 24-inch suitcases without any problem. The mileage at the time of pickup was over 30,000 km, and we drove 1,600 km. The car seemed to be in good condition overall.