Ok - if you have not been out this way before you are in for a shock.
It's a nice place but, like anywhere, you will experience new things, new people and new cultures. This means that you will have to be tolerant - very much so.
The apartment and the car and the tax free salary - great!
But you will need to find out what type of apartment, where it is, what it is like inside etc and the same with the car. I would recommend that you get a 4x4 if the job suits or an executive level car with an industrial grade aircon unit.
The Middle East is a great place but you need to have the creature comforts in place in order to enjoy it. Tax free salary is all well and good but be sure that you have enough. You will be eating out here a lot more and everything is expensive unless you are eating shawarmas off the street.
Your best bet is to let us know what you are getting package wise and then maybe DivingDuck or one of the AD experts can give you their opinion.