It is generally believed that Egyptians drive on the right, although many choose to drive along the middle of the road. The most essential component of an Egyptian driver's car, and all related etiquette, isn't anything mundane to do with safety, the build quality of the car, an engine, or a steering wheel - it is the horn!
The horn is sounded to warn of approach, greet friends, move offending camels, donkeys, street vendors, pedestrians, children and other road users out of the way, allow another road user onto the road (rarely), and just because they feel like it. They also use it to warn the poor unfortunate traffic policeman (strategically positioned at every junction because Egyptian drivers are either colour-blind or don't understand what the significance of a traffic light is) that the driver has absolutely no intention of slowing down or stopping, mostly because they couldn't even if they wanted to.
The general maintenance of the horn is prized above all else, including the inclusion of water in the radiator, petrol, or whether the vehicle still has the correct number of wheels.