The car rental security deposit between AED 1000 - AED 10,000 is taken at the start of rental. It is released max 30 days after the car is returned. It may be returned to you by bank transfer, cash deposit into your bank account or cheque. Security block by credit card pre-authorization is better as it is automatically released by the bank on the same credit card within 30 days.
You will be charged AED 5upon crossing every salik (toll) gate. You will be billed at the end of your rental duration. The salik amount may be deducted from your security deposit or you can pay for it separately.