My friend's experience he shared with me...
National car rental in qatar is a worse car rental. bad talking customer car staff with no knowledge of what they are doing. customers have to teach them their jobs. doubtful statement of accounts. hidden charges. rental counter people does not know to read and explain about the rentals and customer accounts. doubtful behavior of all the staff. overall BAD SERVICE. not answering the call for urgency. rental staff are fighting with customers.

There are other car rentals with good service. finally he took a car from Prestige car rental a which is the best as he said.