Some rent a car has their own rules. here's a useful link for you to know.

http://www.gulf-times.com/site/topics/article.asp?cu_no=2&item_no=168936...

Jail, stiff fine for driving without a valid licence
Published: Sunday, 26 August, 2007, 12:10 AM Doha Time
By Nour Abuzant
ANY motorist convicted of driving a vehicle without a valid licence could be sentenced to a jail term ranging from a month to three years and a fine from QR10,000 to QR50,000, or one of them, the new traffic law says.
The yet to be enforced law says that if a motorist "repeats" the same offence and is convicted by a court, the offender would be sentenced to imprisonment and a fine, both of which could not be suspended or waived.
The jail term, in this case, can range between a week and three years and the fine from QR20,000 to QR50,000.
The law defines "repetition" as committing a similar crime within a year from the day of serving the punishment for the first violation.
In all cases of repeated convictions, the minimum penalty would be the double of the previous punishment.
Driving without a licence is one of the violations which cannot be settled by paying fines. This offence is automatically referred to a court of law.
Citizens of GCC countries who hold valid driving licences issued in their countries can drive on Qatar's roads. If their licences expires during their stay in Qatar, they can be substituted by licences issued locally.
Visitors and tourists of all nationalities, holding valid driving licences issued in their countries can drive in Qatar provided they get the approval from Qatar's traffic authorities within 15 days of their entry into the country.
ACCORDING TO THE NEW LAW, HOLDERS OF VALID INTERNATIONAL LICENSES CAN DRIVE VEHICLES IN QATAR FOR ANY PERIOD WITHOUT BEING SUBJECT TO FURTHER PROCEDURES. The old law gave them only six months and they needed special permission to drive beyond this period. According to the amended new traffic law, which was issued on August 6 but is yet to come into force, insurance companies cannot refuse applications for third-party insurance. If they do, they would be liable to a fine of QR10,000.
The penalty will be doubled if the same company refuses to accept another application for third-party insurance within the next six months after the first conviction.

"When you believe in things that you don't understand, then you suffer...Superstition ain't the way, no no no..."
Stevie Wonder.