Cars older than 4 year are not allowed. If you live in Dubai there are many recovery vehicle owners in Al Awair Area. They charge you AED 2500 to 2800 for overnight shipment and the import duty is approximately 2%. You will have to get an export number plate from Dubai Maroor for AED100 and AED50 for inspection. The export plate will only be issued to a resident permit holed in Qatar.