Effective with model year 2011, and for each subsequent model year, compliance with the California Fleet Average Greenhouse Gas Requirements shall be demonstrated by each motor vehicle manufacturer. Compliance with §A of this regulation shall be based on the number of vehicles, subject to this chapter, produced and delivered for sale in Maryland by each manufacturer. Regional Compliance. The Secretary may enter into a regional compliance agreement with vehicle manufacturers or other states implementing the California Standards. Upon the effective date of a regional compliance agreement, motor vehicle manufacturers that comply with the provisions of the regional agreement shall be deemed to comply with the provisions of §A of this regulation. The Secretary may not enter into a regional agreement that results in lesser emission reductions than would accrue in the absence of such an agreement or that allows manufacturers to use emission reduction credits more than once for regional or State specific compliance demonstration.