Visitors and tourists driving private cars in the UAE

• Visitors and tourists to the UAE cannot exchange their home country licences, but those who hold a licence from one of the free exchange countries might be permitted to drive private cars with their home country licence while visiting the UAE.
• This might only apply to visitors entering Dubai (for other emirates the visitor might need an IDP, and have to apply for a temporary driving licence).
• This might only apply to first degree relatives of the car's owner (mother, father, brother, sister).
• This might only apply if driving the car within the emirate of Dubai, and the car is registered in Dubai.
• Check with the RTA in Dubai, and/or police in the emirate which issued the visit visa or where the private car is registered. Tell them where your car is registered, your nationality, your visitor's nationality, their relationship to you (just say "friend" if boyfriend or girlfriend), and where they will drive the car. Then phone again the next day to talk to someone different and to see if you get the same answer.
• For driving rental cars, slightly different rules apply - an IDP and/or home country licence is required, but not a temporary driving licence.

Why all the "mights" and "maybes"? Because it's difficult to get consistent answers from official sources. If you want to take the safe route, either your visitor should rent a car, or they should go to the RTA or Dubai Police and get a temporary licence. Then get something from your insurance company in writing that they are covered.