Whenever any person is aggrieved by any decision of any county director of finance under this part, the person may appeal from the decision of the director of finance to the district court of the circuit in which the county is situated, by filing with the court, within twenty days after the decision, or within such additional time as may have been consented to in writing by the director of finance, an informal notice of appeal setting forth the name of the appellant, the circumstances attending the decision, a general statement as to the ruling appealed from, the date of the decision, and a description of the motor vehicle involved, with the serial or motor number or both, if available. A copy of the notice shall be served upon, or mailed, postage prepaid, by registered mail with request for return receipt, to the director of finance within two days after the date of the filing with the court. Informalities in the notice shall not invalidate the notice, and the notice may be amended for good cause shown to the satisfaction of the court.