The staff are very patient and meticulous, they record all the old damages on the car during pickup and do the same during return. However, make sure you test the car thoroughly yourself. The wipers on the car I rented weren't working well, which is a concern during Thailand's rainy summer. Fortunately, the rental company noticed the issue with the wipers during return and didn't make a fuss. Also, since Thai people don't speak English very well, it's best to have a real-time Chinese-Thai translation app.