(c) The south coast district shall have the responsibility for preparing and analyzing the portions of the plan elements relating to existing air quality, emissions data, results of air quality modeling, and stationary source control measures. The south coast district shall combine its portion of the plan with those prepared by the Southern California Association of Governments. In consultation with the south coast district board, the Southern California Association of Governments, and other appropriate local agencies, the state board shall provide the emissions reductions attributed to technological vehicular source control strategies included in the plan.