I have a car on my name, but as I can't drive I need to let another person drive the car. This person is not under my sponsorship. He is just a guy who drives the car for me from time to time. I wrote him an authorization letter with my iqama number telephone, signature, etc. just in case he had a problem, since he's driving the car of another person. A few days ago, the police stopped him but they did not accept the letter as proof. Does anyone know how to make an official or valid authorization? Should I talk to a lawyer?