I think you can only drive on a UK licence for 1 week, after which you need to get a Qatar licence, but that is quite easy, can be done in about 1 hour, you need to take a simple eye test and show your UK licence and pay a small charge (QR100 ish), even on a visit visa. Alternatively get an International Driving Licence before leaving UK. I think you can drive 6 months on that. For a cheaper, longer term rental company we use Petra. Warning: for any hire/lease company here, check everything on the car, including the condition of tires, does it have a spare, a jack, a tire wrench? If you need a child seat, bring it from the UK. http://petrarentacar.com