upto 3 months the monthly rate usually applies.

You have three choices really...

Small independent rental companies... usually around 1600-1800 but you have to be careful of insurance xcess... and some companies make u pay for hire while the car is being repaured if the accident was ur fault. Cars are usually older than a year and not well maintained

Large Local rental companies... like al-muftah, al mannai etc. Not sure but should be a bit better than the small companies in terms of quality of cars

International companies like Hertz, avis, europcar usually offer full insurance but the rates go up to around 2000 a month. but piece of mind cost money. Cars are usually very new.