All I can go by is the in formation I was given, correct or not, when I moved here.
I was told the car had to be less than one year old and could be brought in tax free if the company you worked for was allowed it to be so.
But then you have problems selling it on depending on how long you keep it for. Again there is conflicting information about this.
There are many cars here that are as in Europe, but you pay a premium for them. You can buy new and second hand, but the taxes are a bit of a killer. Or you can buy the cheaper Asian/Chinese/Eastern European equivalent.
Bringing in on a Carnet does present the time limit problems. There is a poster here called Jamie-T who had his Landcruiser here for some time, maybe he knows a way round it.
The thing about Egyptian nationals being exempt from tax I'd take with a pinch of salt. I could be wrong but I don't think so otherwise they'd all be at it.
There a several companies that'll get you a tax free car, but it has to be brand new. I bought a Pajero as I knew they were popular here, however I made the mistake of getting a diesel, and they aren't. Thus I have problems always getting normal engine servicing parts, I can get them but they're not common at all.
I got it via a Scandinavian company and it came direct from Japan to Alexandria.
The short answer then, is, I can't really help you.