If, in accordance with this subpart, the Administrator allows a settlement of a case of violation of an average fuel economy standard, an order of settlement shall be issued, setting out the terms of the settlement, and containing a brief discussion of the factors underlying the exercise of the Administrator's discretion in allowing the settlement, including a discussion of comments received under § 511.65. If the Administrator rejects a petition for settlement, the Administrator shall give written notice of the rejection and the reasons for the rejection to the parties and the Presiding Officer.