Before finding a parking space you should check that it is safe to park and it is allowed. You will see parking signs that will state the allowed time to park. When parking in Dar on your return a parking attendant will approach you for payment. The attendant will either hand you a ticket, or a ticket will already be on your windscreen.
At night, you are only allowed to park on the left hand side.
Tanzania does not have a Parking Permit scheme.