402.7. A person is not entitled to the rebate provided for in section 402.6 unless1° the person files an application for the rebate within four years after the date the tax was paid; and
2° the application for a rebate is accompanied by a medical certificate describing the individual’s handicap for which the automatic door opener was acquired and indicating that the individual cannot, unassisted, gain access to the individual’s residence without such a door opener.