Exemptions.

The department may grant an exemption from compliance with the standards of this part for any currently produced product model which the manufacturer shows, and the department finds, comprises less than 0.5 percent of that manufacturer’s total sales volume in the state for that product class, and with respect to which the manufacturer shows, and the department finds, that modification of the product model to meet the standards of this part would place an undue burden on the manufacturer. Such determination by the department shall be considered final agency action reviewable pursuant to chapter 120. An exemption so granted shall be for a period of up to but not exceeding 2 years. The department shall grant only one exemption for any particular model, and any new product model initially produced after January 1, 1988, shall not be eligible for such an exemption.